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HACK ’N SLASH COMBAT DESIGN HOW COMPLEXITY IS BUILD UP

BY BART VOSSEN portfolio: http://bartvossen.weebly.com

Abstract This paper deals specifically with the complexity of combat systems within hack ´n slash games. The focus will be on researching ways to increase and decrease the complexity of a combat system to make it more challenging or more accessible. I will only focus on the player’s side, not the enemies. Utilizing the findings of my research, I will attempt to formulate and propose possible solutions to implement different levels of complexity within the same game. This framework should also be valid within any game which uses melee combat.

INTRODUCTION For the purpose of this paper the term complexity will refer to how much the player has to learn to be able to use the combat system effectively and how difficult it is for players to use it as they intend to. This is affected by the amount of available and viable options, how difficult these are to perform reliably, when each move can be used and how effective they are in each situation, and how easy it is to make mistakes.

Throughout the paper I will use the terms attack, move, and combo. I will shortly describe these terms to prevent any misconceptions.

ATTACK An attack, for the purposes of this paper, is an offensive action which the player character does when the player presses a button (or a combination of buttons pressed simultaneously).

MOVE A move is usually a short string of attacks wherein each attack requires its own button press. Although in some cases a move will consist of one attack. Each attack is usually also different and unique for that specific move. Hack ‘n slash games generally have a move list which players can view in game to see all moves available.

COMBO A combo is a chain of moves executed quickly one after another before getting interrupted. Combos often focus on a single enemy and keep that enemy in a state where they can’t avoid the consecutive attacks or moves. Although in certain cases combos can target multiple enemies and have short periods of time in between attacks during which enemies can respond.

GAME ANALYSIS For this paper I analyzed three different hack ‘n slash games; God of War 3, Ninja Gaiden 2, and DmC Devil May Cry (DmC). I choose these three games because they are well known and are released for the current generation game consoles. These games were also selected because of

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how difficult they are proclaimed to be. One being perceived as easy, one being perceived as hard, and one in between.

God of War 3 God of war is a hack ‘n slash game; a third person action adventure game with a focus on melee combat. Besides the regular combat the game includes platforming and climbing sections and puzzles in between fights, and quick time events to finish stronger enemies and bosses. The game has fixed cameras . God of war is seen as an easy and accessible hack ‘n slash game and is aimed at a wider audience. The players play as Kratos and join him on his quest for revenge, climbing mount

Olympus and killing Zeus. The game’s focus is on brutal combat and making the player feel powerful with everything they do.

Most of the combat is done with the weapon the player has selected; throughout the game players unlock a few weapons which they can use. Besides that the player also has a bow for ranged attacks, one magic skill which varies between weapons, and the Rage of Sparta which momentarily boosts Kratos’s powers. Players can block attacks and get out of harm’s way by means of a dodge roll.

Ninja Gaiden 2 Ninja Gaiden is a hack ‘n slash game, similar to God of War 3. The main focus of the game is the combat with a large variety of weapons, enemies and bosses. The player plays as Ryu, a master ninja who is on a quest to save the world from the archfiend. In between combat encounters there are often short sections where the player performs ‘ninja’ actions,

such as wall running, giving players the feeling they really are a ninja. The game has a free camera and it even allows players to look around in first person (this is only possible while standing still).

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Ninja Gaiden is perceived as a very difficult and hardcore game. This is mainly because of the difficulty and unforgiving nature of the combat system. Players mainly fight with their melee weapon of choice, starting the game with a katana. Each melee weapon also has an ultimate attack which has to be charged by holding Y or Triangle (Xbox or Playstation controller, respectively). The ultimate technique charges faster when the player just killed a few enemies. Players also have a few ranged weapons and Ninpo at their disposal, both of which only one can be equipped. Ninpo are strong attacks which consume Ki charges when used. Players also have the ability to use items to restore health and Ki.

DmC Devil May Cry DmC is a hack ‘n slash game; a third person adventure game with a heavy focus on melee combat. Besides the combat the game features some platforming sections and small puzzles. There is also an element of exploration present as players can search for keys which grants them access to specific challenges. Players play the game as Dante who is the son of an angel and a demon. He constantly goes in and out of Limbo to fight off all enemies send at him.

DmC is perceived harder than God of War as the combat is more complex, yet it isn’t as hard and unforgiving as Ninja Gaiden.

In DmC players fight with four different weapons simultaneously. One can be described as the normal weapon, the second is a demon weapon which focuses on damage, the third is an angel weapon which focuses on attacking large areas, and the forth is a pair of guns which are used as range attacks. The main focus of the combat is to perform combos while avoiding enemy attacks.

SIMILARITIES There are several similarities between the combat systems of these three games, and most hack ‘n slash games (or games with melee combat systems). Even though these are similar in all three games, there are still small differences. I will first describe these similarities, how they can affect the difficulty, and the small differences between the games. Then I will give a critical analysis describing the best ways to implement varying complexity and what to avoid.

ATTACK ANIMATIONS The animation of an attack is split up in three parts; the anticipation, the hit frames, and the cooldown.

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ANTICIPATION This is the start of an attack and its animation. The player character is already attacking but the hitbox isn’t active yet. For example an attack with a sword starts with the character lifting the sword and putting it in position to slash as hard as possible. The way the anticipation looks sets the players expectations for the rest of the attack, how strong the attack is, and what additional effects the attack can possibly have.

The first thing players can recognize from an attack is the anticipation. Thus it’s the first form of feedback players get in whether they perform the attack they intended to perform.

Effects on Complexity During the anticipation the player is vulnerable for attacks from all directions. This means that if players attack at the wrong moment their attack can be interrupted. The player can’t do anything against this unless the attack can be cancelled. Because of this an attack gets increasingly difficult the longer the anticipation takes. In case players can’t cancel the attack they are vulnerable for a longer amount of time. In case they can cancel the attack they can still respond to enemies, however cancelling the attack will prevent the player from hitting it.

HIT FRAMES This is the attacking part of the animation. During the hit frames the hitbox is active and can hit enemies. For the sword attack example this would be from the start until the end of the slashing motion. Enemies can only be hit once while a hitbox is active (more on this in the Hitboxes section). Certain attacks have more than one hit. Meaning there are one or more sections in between the hit frames where the hitbox isn’t active. Each section of hit frames is a hit. The sections in between the hits are anticipations for the next hit. In most cases these anticipations are very short.

Effects on Complexity If an attack has more hit frames it becomes somewhat easier to hit as there is more time for enemies to move into the hitbox. This can be because the enemy moves into it themselves or because they are still in a different animation, like falling for example, wherein they automatically move. If an attack has

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more hit frames it gives players a bigger window to get the timing of the attack right. This makes it easier for players to move the player character as they intend to.

During the hit frames the player can still be vulnerable for attacks depending on the hitbox of the attack. For example if the hitbox is in front of the player enemies can still attack from behind. (More on this in the Hitboxes section.)

COOLDOWN This is the final part of the attack and starts after the hitbox stops being active. During this part of the animation the player character returns to its neutral stance. For the sword attack example this would start at the end of the slashing motion and end when the attacker has taken his original stance. The cooldown is the conclusion of an attack and can enhance the feeling of the attack. For example a strong heavy attack would have a longer cooldown while a quick strike would have a very short cooldown.

Similar to the anticipation, the player is vulnerable for attacks from all directions during the cooldown. The player can’t do anything against this unless it can be cancelled by something else (more on this is the Attack Cancelling section). In contrary to the anticipation, the player can have already hit enemies with the attack before the cooldown starts. This means that those enemies most likely can’t attack the player because they’re in hit stun (more on this in the Hit Stun section). Cooldowns are in general longer than the anticipation.

Effects on Complexity Again, similar to the anticipation, the longer the cooldown of the attack the more difficult the attack is. However this is also influenced by other factors such as cancelling and hit stun. Cancelling won’t prevent the attack from hitting, as it does during the anticipation, and thus has less downsides. Cancelling during the cooldown does also end a move and thus the following attacks can’t be executed (more on this in the Moves section).

Hit stun prevents enemies from attacking the player and thus there is less risk involved in the vulnerability. This means the player is more vulnerable during the cooldown when they missed the attack than when they hit, and the more enemies they hit the less vulnerable they are during the cooldown.

ATTACK COMPONENTS

HITBOXES Hitboxes are cubes, spheres, or other 3D shapes, which are invisible to the player and are used to detect whether an attack hits something. Characters also have their own hitbox to detect whether they are hit by an attack. For the player’s attack to hit an enemy, the hitbox of the attack has to hit the enemy’s hitbox. The same goes for enemy attacks hitting the player.

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Effects on Complexity As described before, the duration an attack’s hitbox is active influences how easy it is to hit an attack. Yet the size and movement of the hitbox play a much bigger role. The bigger the hitbox, the easier it is to hit an enemy with the attack. Additionally the hitbox often moves along with the weapon during the animation of the attack. As a result the movement of the hitbox also influences how easy it is to hit the attack. The more the hitbox moves the greater the area is which gets hit and thus the easier it is to hit the attack. Horizontal moving hitboxes also have a greater chance to hit than vertical moving hitboxes as enemies usually move alongside a horizontal plane; walking on the ground or flying on the same height.

Besides the chance to hit an attack, hitboxes (and thus attacks) can also be used defensively. If an attack hits everything in front of the player, that attack can be used to defend against enemies attacking from the front. Therefore attacks which hit a larger area around the player are easier than attacks which only hit in one direction.

HIT STUN AND KNOCKBACK When the player, or an enemy, is hit by an attack there will be an animation playing of being hit during which the player, or enemy, can’t do anything. This is called hit stun. The duration and which animation is playing varies depending on the situation; which attack is being used, is the player blocking, or in a different state. Additionally enemies, or the player, can get pushed in a direction as a result of being hit by an attack. This is called knockback. In case the attack has no knockback the hit stun prevents the enemy from moving. Usually hit stun also stops the movement of enemies in the air (more in this in the air combat section).

When an attack is blocked there is usually also a short hit stun. This hit stun is a lot shorter than when the attack isn’t blocked. During this hit stun the player will remain blocking.

Frame Advantage The effectiveness of hit stun partially depends on the cooldown of the attack. For the player’s attacks a longer hit stun makes the combat easier and less complex as enemies are defenceless for a longer amount of time. Yet the player cannot instantly take advantage of this due to the cooldown of the attack. The difference between the cooldown and hit stun duration is called frame advantage if the cooldown is shorter. The player can use this time to do whatever they planned next before the enemy can do anything. The bigger the frame advantage the easier the combat. In case the hit stun is shorter, the enemy has a frame advantage. This heavily increases the difficulty if the player performed the attack. In case an enemy hits the player the same applies; a higher frame advantage for the player is easier, and higher frame disadvantage is harder.

Knockback Knockback usually pushes the player away from the enemies, or the enemies away from the player. This often creates a short pause in the combat which gives the player a moment to think through what they are going to do next. In some cases, when the player is surrounded by enemies, it can push the player into other enemies and thus there’s no pause in the combat. Whether knockback makes the combat easier depends on the situation. In case the player wants to keep attacking enemies knockback would work against them as it pushes the enemies out of the attack’s range. Thus, less or no knockback makes it easier to keep attacking. However, in case

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the player wants some room to breathe more knockback gives them more time and thus makes it easier.

INTERRUPTING Ending an attack (or other action) prematurely as a result of getting hit by something. Usually players get interrupted whenever they get hit by an enemies attack, except when they are blocking. Players can also interrupt enemies by hitting them with attacks. Some specific enemies or bosses can’t be interrupted or can only be interrupted by specific attacks. When an enemy or player is interrupted they receive hit stun and possibly knockback, depending on the attack.

Interrupting enemies is very useful for the player as their attacks can be interrupted as long as the player hits first. However, this also goes for enemies. This means that attacks with a short anticipation are very useful for interrupting enemies. The more chance the player has to interrupt enemies and the less chance enemies have to interrupt the player, the easier the combat is. The shuriken in Ninja Gaiden, for example, are a tool to interrupt enemy attacks as they are fast and ranged. Some attacks cannot be interrupted, like the Army of Sparta in God of War, which makes them very easy to hit or to use as a defensive action.

PLAYER CONTROL

ATTACK CANCELLING Ending the attack prematurely and performing another action instead is called cancelling. Though this isn’t limited to attacks, it is mostly used for attacks. The most common way of attack cancelling is in moves, where the cooldown of an attack can be cancelled by the next attack in the move (more about moves in the Moves section). This is also the only attack cancelling seen in Ninja Gaiden. In God of War and DmC attacks can also be cancelled by dodging, blocking (only in God of War), and jumping during the cooldown and the anticipation. Not being able to cancel attacks is one of the reasons why Ninja Gaiden is so difficult.

Being able to cancel, and when and how, has a lot of impact on the difficulty of attacks. Additionally it also increases the responsiveness of the game, as the game will more often instantly react to the input of the player. Being able to cancel an attack by a defensive action, such as blocking, dodging, or jumping gives players more opportunities to respond to what the enemies do. It also gives players the chance to correct their mistakes in case they are using the wrong attack. Thus being able to cancel moves makes the game easier and feel more responsive. Usually cancelling is divided in the specific sections of the animation: the anticipation, the hit frames, and the cooldown. Being able to cancel during all three sections would make the combat even easier. In God of War the cooldown can also be cancelled with walking. This adds to the responsive feel as player can switch quicker between attacking and moving around. Attacks usually can’t be cancelled by other attacks except for the aforementioned moves. Other animations such as starting a jump, landing, falling, and dodging can in some cases also be cancelled. This makes the combat easier and the game feels more responsive. It allows players to switch faster between moving around and attacking.

In case the animations can’t be cancelled the combat becomes more difficult and complex. Players won’t be able to correct mistakes and thus get punished a lot more for making a wrong move. Players also can’t instantly respond to enemies or their surroundings. This means players have to plan ahead more carefully and be able to predict what enemies are going to do.

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INPUT BUFFERING Whenever the player presses a button that has to be processed by the game. These inputs will be placed in a buffer from which the game detects whether a certain attack has been performed. The most important part of the input buffer is that players can place input in the buffer while the player character is still performing an action. This means players can perform the input for the next attack while the current attack is still being executed to make sure the attack instantly starts after the current attack. It makes timing easier and makes the game feel more responsive. The input buffer always performs the last action placed in the buffer first. This way players can correct their input in case they press the wrong button first.

Input isn’t stored in the input buffer forever. It usually is stored about a second before getting removed from the buffer. The longer input is stored the more leeway players have in their timing. This makes it easier for players to give the correct input for the attacks they want to perform. The shorter the input buffer is, the more difficult it becomes to get the timing right and perform the attack when the player wants to.

OTHER

MOVES As described before moves are strings of attacks, or a single attack, consisting out of different attacks usually unique to that move. Hack ‘n slash games generally have a move list where players can view the moves available to them. Each weapon has its own move list and allows unlocking moves in some way. This is usually done by levelling up the weapon (God of War and Ninja Gaiden) or buying individual moves (DmC).

For moves which exist out of multiple attacks, attacks within moves usually cancel the cooldown of the previous attack. If the player waits for the correct button input until after the cooldown they are usually too late to perform the next attack in the move. In case the player cancels any of the attacks of a move, by something else than the next attack in the move, they also stop executing the move besides stopping the attack. This means that the first attacks of moves are used most often while the last attacks are used less often. It also means the later attacks of a move are more difficult than the first attack as there is a bigger chance that something ends the move prematurely.

Some moves will require a short pause in between the input, which is something only seen in DmC and none of the other games analyzed. These pauses are often a split point in between moves, where for example move A gets executed without the pause and move B gets executed with the pause at a certain point. These pauses increase the complexity and difficulty. They require more precise timing which makes them harder to execute.

The amount of moves in the move list also increases the complexity of the combat system. Players will have to learn the commands for each move, being able to execute them reliably. After that they have to learn in which situation each move can be used. Thus the more moves exist the more the player will have to learn. Do note that players usually don’t have to learn all moves and their optimal use to be able to complete the game or play effectively.

AIR COMBAT

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Air combat means performing attacks while in the air. All three games have a jump button and allow the player to perform attacks while in the air. Air combat greatly differs from ground combat. In the air players have less mobility and less control over their movement; gravity always pulls them down and they can’t change direction in the middle of a jump. The amount of jumps is also limited to one or two, depending on the game. Air combat does have advantages over ground combat. The player becomes harder to hit for enemies as being in the air usually puts the player outside the enemy’s reach. Only enemies who can also attack in the air or who have greater range with their attacks can hit the player.

When players use an attack, while being in the air, their falling speed usually heavily decreases. Some attacks even move the player higher into the air. This way the player can stay close to the enemy after the attack, assuming the player is close to the enemy when attacking. It allows players to perform moves which consist of multiple attacks in the air and hit the enemy with each attack. If the movement of the attack doesn’t keep the player close to the enemy, it becomes harder to hit enemies with consecutive attacks. This can be either by the enemy receiving knockback or the enemy or player continuing to fall. In case both the enemy and player continue falling, regardless of hit stun or the attack, it becomes easier. Yet it’s still harder than the attack causing the player to stay with the enemy as the time spend in the air is shorter.

The decrease in falling speed, and some attacks moving the player higher, are ways to prolong the air combat. Most enemies can’t fight back in the air, which makes them vulnerable until they are back on the ground again. This means air combat is safer for the player. In DmC players also have two attacks which pull the enemy towards the player, and the player towards the enemy. This adds manoeuvrability to the air combat, making it a lot easier to stay in the air and possibly avoid attacks. Additionally there are also flying enemies, which makes it even easier for the player to get into, and stay in the air.

SPECIAL EFFECTS Attacks usually have a special effect on them, often in the form of a swipe trail. These effects are used to make the attack and animation more visible to the player. It is important that players get clear feedback on what they are doing. On hit effects are another important part of player feedback. They have to communicate to the player that the attack hit. States and other abilities can be made more clear by giving them their own distinctive effect. This way players will know what is going on. At the same time it helps the player learn what each attack does as it makes it more visible to the player.

Clear and distinctive special effects make the combat easier and less complex as players can detect more easily what is going on. Players will still have to learn what each effect means. In case the effects are distinctive and relate to what they mean it is easier for the player to learn and understand them. Effects which resemble each other too close makes it harder for the player to know what is going on. Effects that don’t relate to what is going on make it harder to learn the meaning of each effect. The absence of any special effects can cause a lack of player feedback, making it harder to know what is going on. The harder it is for the player to understand what is going on, the more difficult the combat system is.

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All three games feature swipe trails on the attacks, clear on hit effects, and effects for special states and abilities. Effects can also help communicate what will happen if they press a button. In God of War, when the player uses an attack with the Blades of Exile, they get a red burning glow. This glow lights up the area a little bit and helps in making the attack easier to see. The glow also communicates to the player when they can still use the next attack of the move, as when it disappears they can´t start the next attack of a move. DmC has something similar to communicate the input pauses for certain moves. The moment the player waited long enough with the input a short effect appears on the players weapon indicating this change of state. Both these effects make the combat system slightly easier as they communicate useful information to the player.

SIMILARITIES – CRITICAL ANALYSIS In my opinion there are several components which are important regardless of the desired complexity. Each attack should have an animation split into an anticipation, hit frames, and a cooldown. The anticipation is a vital part as it is the first feedback the player receives by which they can determine they executed the attack they wanted. Each attack should have a clear, distinct anticipation to prevent confusion. It is also important to set the right expectations with the anticipation. The hit frames are the core of the attack. It should be clear from the animation which frames are the hit frame. Players will try to hit during these frames of the animation, thus it is important the player can see when this is. It is also important that the hitbox is clear to the player during this part of the animation. The weapon is a clear indication, and for other locations projectiles and special effects can be used. The hitbox should never be smaller than the weapon, as this goes against player expectations. The cooldown is important as it returns the character to their neutral stance, while concluding the animation to give the attack the right feeling. The cooldown also provides players with a small window during which they can input the commands for the next attack within the move.

When an attack hits a regular enemy they should, in my opinion, be interrupted and receive hit stun and knockback. Bosses and the special attack of specific enemies don´t have to follow this rule, yet that does make these opponents harder to defeat. Interrupting enemy attacks is an important way for players to defend themselves. Attacks which cannot be interrupted should be clearly signposted. The duration of the hit stun and the distance the enemy is knocked back should vary per attack. This should also follow the expectations set with the animation of the attack. These can be used to increase the complexity by giving the player a frame disadvantage for some attacks if they aren´t used in a combo. Enemies often receive more hit stun if they are hit by consecutive attacks in a combo. This is a good way to make certain attacks more effective during combos, yet does increase the complexity.

Special effects are vital for player feedback and should, in my opinion, always be implemented. They add to the animation of an attack, enhancing the feeling of the attack and giving feedback about the effects of the attack. They are used to give clear feedback when an attack hits. They

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should be used to clearly indicate special states, abilities, and effects. These should all have special effects which players can relate to what they mean, and which players can easily keep apart. In my opinion special effects have to be implemented regardless of the complexity to give clear feedback to the player. The visual appearance of these effects should fit with the style of the weapon and the rest of the game. A lack of special effects can cause a lack of player feedback, which can leave the player confused to what is going on. This should be prevented.

In my opinion an input buffer is necessary for the combat system as it gives players more time to input the commands for their next attack. It makes the game feel more responsive as it allows players to input their next move while the current attack isn´t finished yet. It also gives players more leeway in timing their input right. The time input is stored depends on the desired complexity.

The moves, attack cancelling, and air combat are the best methods to implement a certain level of complexity. The number of moves and use of each move can vary greatly. A few moves, each with a clear and distinct purpose is a lot less complex than giving the player a larger set of moves which more closely resemble each other. Players will have to learn all these moves and their uses. Fast hitting moves with longer hit stun also make it easier for the player than slower moves. Attack cancelling can be used to make it easier for players to respond to their surroundings or correct their mistakes. The easier it is for players to cancel their moves with defensive manoeuvres, the less complex the combat system. Being able to cancel the cooldown of attacks by other attacks allows players to keep attacking more, and allows for more combo oriented gameplay. Not being able to cancel attacks is one of the reasons why Ninja Gaiden is difficult, while for God of War being able to cancel attacks is one of the reasons why it is easier. Air combat affects the complexity in how easy it is to get in the air and remain in the air. As players already have a slight advantage in air combat, giving them options to stay in the air longer and to move around decreases the complexity. Though this should be used with caution as it can cause players to only fight in the air. The ease with which players can stay in the air in DmC is partially the reason why it is easier.

DIFFERENCES There are also differences between the three games, most of which can be put in similar categories.

DEFENSIVE OPTIONS The three games I analyzed all have defensive options. These give the player the opportunity to escape or avoid a dangerous situation. The ones used vary between the games. In general there are two defensive options; blocking and dodging. Additionally some attacks can have invincibility frames. These are short periods of time during which the player cannot be hit.

BLOCKING In both Ninja Gaiden and God of War players can block. This prevents damage and has a faster recovery time (a shorter hit stun). Though not all attacks can be blocked; some enemies have powerful attacks which break through the block or ignore it entirely. Players can still be grabbed by enemies while blocking. In Ninja Gaiden, when the player is blocking they instantly turn towards the enemy who attacks them, automatically blocking attacks from all sides. However

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when they get attacked from two sides simultaneously they still get hit. In God of War the player doesn´t turn and blocks all attacks, even if he is attacked from multiple directions at once. This makes the blocking in Ninja Gaiden more difficult than in God of War. In Ninja Gaiden each enemy also has a grab attack which they use occasionally when the player is blocking. This makes it even more difficult. The easier it is to block and remain blocking, the easier the combat system is as it allows players to defend more.

In God of War players can also parry by timing their block right before the attack hits. In case the attack is a projectile, it is reflected back at the enemy. In case it is a normal attack the enemy gets pushed back and there is a short window in which the player can perform a counter attack which will hit all nearby enemies and create some room for the player. This creates a risk reward scenario where players have to decide what they want to do. In Ninja Gaiden players can counter attack by pressing an attack button while blocking. In case the timing is right they will successfully perform a counter attack. If their timing is off they are vulnerable for a short amount of time. This also creates a risk reward scenario similar to God of War. The difficulty depends on how precise their timing has to be and how long they are vulnerable after failing. The more precise the timing has to be and the longer they are vulnerable, the harder it gets to counter successfully.

DODGING In God of War, Ninja Gaiden, and DmC players can dodge. Dodging is a quick movement which allows players to try to avoid an attack by getting outside of the attack’s range. The movement speed of a dodge is faster than walking or running yet has a longer cooldown at the end of the animation. Thus after a dodge players are vulnerable for a short amount of time. The longer they are vulnerable, the harder the dodge gets as players are more vulnerable afterwards. The distance traversed with the dodge also affects its difficulty. For a shorter distance there is a higher chance that the player didn’t get completely out of the enemies range and thus it makes it harder to avoid attacks. For a longer distance players can temporarily remove themselves from the fight, assuming the enemies don’t have a way to traverse such distances equally fast. The longer distance makes the combat easier as players can move out of the fight whenever they want to. It also allows for hit and run tactics.

In God of War players perform a dodge with the right joystick in the direction they push the stick. In DmC players perform a dodge forwards by pressing one of the bumper buttons. In Ninja Gaiden players perform a dodge by pressing a direction while blocking. All three dodges are far enough to get outside of the enemies reach. Yet they aren’t far enough to remove the player from the fight. In Ninja Gaiden and DmC the dodge is shorter and faster than in God of War. There they can also be used to quickly move around during the fight. In God of War this is less effective as the dodge takes longer.

RANGED WEAPONS Even though this paper focuses on melee combat, hack ‘n slash games usually also include a form of ranged attacks. These are performed with weapons such as the bow, and all shoot projectiles. In some cases these attacks can still be used effectively in close range such as the shuriken in Ninja Gaiden 2 and the guns in DmC. The functions and uses differ per weapon and per game.

All three games have auto targeting on the ranged weapons, usually to the closest enemy straight in front of the player. Ninja Gaiden also allows you to aim more precisely by aiming in

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third person. Players will sometimes have to use this to hit specific objects in the level to progress. In God of War players can charge the ranged weapons, which perform a different attack when fully charged. For example the bow shoots a fire arrow instead of a normal arrow. During the charging players receive clear visual feedback indicating which enemy will be hit by the attack. Players can then turn slightly to switch between targets. In DmC and God of War players can also turn around to go for a different target, yet in DmC there isn’t such clear feedback as in God of War indicating who is targeted. The auto targeting makes the use of ranged attacks a lot easier, compared to having to aim. It allows players to use the ranged attacks faster, as they don’t spend the time they would otherwise use to aim.

In all three games the ranged weapons can be used during combos. There they can be used to stun the enemy, as with the shuriken in Ninja Gaiden, the bow in God of War, and the guns (Ebony and Ivory) in DmC. The stunning allows the player to prolong the combo and add a little extra damage. Other ranged weapons are more aimed at dealing more damage on long range. As a result they are less useful in combos. Or they are for dealing more damage on short range, which gives them a different use. The Revenant in DmC is a powerful short range shotgun which can, for example, be used to knock back enemies at the end of a combo. The complexity added by the function of each ranged weapons depends on the amount of ranged weapons. Adding more ranged weapons, and giving them more moves, increases the number of things players will have to learn and remember to utilize every aspect of the combat system to its fullest.

SPECIAL ATTACKS Most hack ‘n slash games also include special attacks which usually require a specific meter or charges. They are powerful attacks which can only be used occasionally. In God of War 3 these are the attacks using magic, in Ninja Gaiden these are the Ninpos, and DmC doesn’t have special attacks. How special attacks work varies greatly between different games.

In God of War players have one special attack per weapon. In Ninja Gaiden players can equip one special attack, yet they can choose which one they want to use independently from the weapon they select. Setting the special attack per weapon limits the players choice in selecting a special attack.

In God of War each Special Attack uses a certain amount of magic which varies between attacks. The amount the player has is shown in a bar below the health bar. Players collect blue orbs to recharge this bar. In Ninja Gaiden each special attack uses one Ki charge, which are also shown below the health bar. Players collect red orbs which recover one Ki per orb. The charges give players more clear feedback on how often they can use their special attack. The differences in the magic bar are smaller and thus harder for players to accurately estimate.

CONTROLS Hack ‘n slash games are, just like most video games, played by players who influence what happens in the game by pressing buttons on controllers. In hack ´n slash games players control the player character´s actions with the controller. The control layouts, which action is performed by which button, vary between different games. It greatly influences how complex the combat

2013 14 by Bart Vossen

system is. Players will have to learn these controls to be able to do anything in the game. There are similarities and differences between the three games I analyzed.

In general players move with the left stick and control the camera and/or evade with the right stick. Jumping is usually the A button on the Xbox 360 or X on the PS3. X, Y, and B on the Xbox 360 and Square, Triangle, and Circle on the PS3 are usually used for attacks. Blocking and other mechanics are put on the bumpers and triggers. The D-pad on the Xbox 360 and direction buttons on the PS3 are usually used for switching weapons.

God of War mostly follows these controls, with evading on the right stick, blocking on the left bumper, ranged weapons on the left trigger, magic on the right trigger, and the rage of Sparta can be activated by pressing on both joysticks. Additionally players can interact by pressing the right bumper.

Ninja Gaiden also mostly follows the general controls, with camera controls on the right stick, projectiles on the B button, Ninpo on the Y and B button simultaneously, and blocking with the left trigger. Additionally players can interact by pressing the right bumper, go in first person view by holding the left bumper, and reset the camera with the right trigger.

DmC also mostly follows the general controls, with camera controls on the right stick, ranged attacks with square, evading with the bumpers, activating devil trigger by pressing both sticks, and entering angel mode and demon mode by pressing the left or right trigger respectively.

Ninja Gaiden uses less buttons for combat which makes it easier for players to learn the controls. The controls of God of War are slightly more complex as it uses more buttons for all combat actions. With the left trigger players can use all ranged weapons by pressing another button, which is something extra players have to learn. Yet DmC has the most complex controls of the three as by entering angel mode or demon mode most buttons perform a different attack than before. This means players have to learn a lot more controls compared to God of War and Ninja Gaiden.

DIFFERENCES – CRITICAL ANALYSIS

2013 15 by Bart Vossen

In my opinion players need a way to defend themselves, a way to avoid dangerous situations. This can be either by blocking, by dodging, or by both. The blocking in both God of War and Ninja Gaiden are good examples. The blocking in God of War is easier as players can block attacks from different directions simultaneously. Though enemies should also be able to still hit the player to prevent them from blocking constantly. Unblockable attacks with clear indications is a good way for lower complexity. This can also be seen in God of War. Letting enemies grab the player is another possibility. In Ninja Gaiden it is harder to spot when an enemy starts a grab, and thus these increase the complexity. Grabs with clear visual cues would essentially be the same as unblockable attacks. Giving players the opportunity to counter attack is a good way to quickly switch between defence and offense, while creating a risk reward situation. In God of War players can shoot projectiles back as well, which can be quite powerful in some cases. Dodging is another good defensive mechanic which works well as it doesn´t only allow players to avoid getting hit by an attack, but it can also be used to move around. Dodging is slightly more complex than countering as players have to take into consideration where they are going. Dodges which traverse a longer distance are good ways to make the combat less complex, as it allows players to create a pause in the action. Short distance dodges, as seen in Ninja Gaiden and in DmC, are better ways to quickly move around during the fight.

Giving players the option to both block and dodge makes the combat less complex. Even though players have to learn more things, it gives them multiple methods to escape dangerous situations. As mentioned before, only implementing dodging is more complex as it is harder to perform successful, than blocking. This is one of the reasons why DmC is harder than God of War. Only implementing blocking does reduce the player´s mobility, which is something that has to be kept in mind. The important part about the defensive options is that they are simple; easy to use and understand by the player.

The controls should be as simple as possible as players will need to learn these first. More complex controls increases the complexity of the game. Yet it can also cause frustration to players, which is something that has to be avoided. The controls have to be easy to learn to allow players to learn the rest. It is best to follow the general controls, as a lot of players will already be familiar with these from playing other games. This speeds up the learning process.

Ranged weapons are a useful addition as it gives players the ability to attack enemies at a longer range. However they should be less effective than regular combat. Auto targeting is vital for ranged weapons, as aiming takes too much time and leaves players vulnerable. Giving an indication as to which enemy is targeted is important player feedback. It is also good to still make the ranged weapons usable in short range to, for example, use them during combos. There should only be a few different ranged weapons, with each only one or two attacks. Otherwise they add to much to the complexity.

Special attacks are an interesting addition, yet not required. They are useful for dealing extra damage or as a defensive tool. “Army of Sparta” from God of War, and most Ninpo in Ninja Gaiden have invincibility frames, and thus can be used to defend. While most deal more damage than regular attacks. Special attacks should be different from regular attacks and should only occasionally be useful. It is better for special attacks to use charges, as in Ninja Gaiden, instead of a meter, as in God of War. Charges give more clear feedback to the player as to how often they can use the attack.

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IMPLEMENTATION There are a few ways in which different levels of complexity can be implemented within a single game.

DIFFICULTY LEVELS Different levels of complexity can be implemented per difficulty level. This means that depending on the difficulty level the player chooses things change within the combat system. As a result the game will play and feel different on each difficulty level.

This does mean that players cannot use anything learned from other difficulty levels as all attacks and moves will be different. This takes away the opportunity for players to practice on a lower difficulty level to prepare for the higher difficulty levels. Players will have to learn the combat system all over again on each difficulty level, which adds to the difficulty in itself.

DIFFERENT WEAPONS Different weapons can have different levels of complexity. This means that players can switch between different weapons, where each weapon has its own list of moves. Each weapon can have a difficulty level giving an indication of how complex the weapon is. A lot of hack ‘n slash games already feature different weapons (God of War, Ninja Gaiden, and DmC all do).

By implementing the complexity differences per weapon players will have the opportunity to practice with each weapon on the lower difficulties. It also gives players an additional choice in determining difficulty, giving them more control on how challenging the game is.

WITHIN A SINGLE WEAPON Different levels of complexity can also be included within a single weapon. In this case the complexity difference will be between different moves. This can be implemented in two ways; either letting the complexity depend on the button used, e.g. one button for complex moves and one button for easier moves. Or let the complexity depend on each individual move. The later would increase the overall complexity as players would have to learn more about each individual attack. While letting the complexity depend on the button means the player only has to learn that all attacks from one button are similar. This decreases the overall complexity, yet is still more complex than using the same complexity throughout the entire move list (and thus either the weapon or difficulty, as described before).

IMPLEMENTATION – CRITICAL ANALYSIS In my opinion the best way to implement different levels of complexity within the same game is through different weapons. It gives players the choice of which weapon they want to play with and thus allows them to choose their own complexity. When different levels of complexity are placed within a single weapon players do not have this choice. Small differences are required within a weapon to make all moves different and give them their own purpose. Implementation via different weapons also allows players to learn each weapon on a lower difficulty level before increasing the challenge by playing on a higher difficulty. This isn’t possible when the complexity varies between difficulty levels.

SOLUTION

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Here I will combine everything described up until now to describe an easy, medium, and hard combat experience and the best way to combine these three within a single game.

EASY An easy combat experience has a low complexity and is intended to be accessible for all players. Players have a few moves at their disposal, each with a clear distinct purpose. Most attacks have a short anticipation, large hitboxes, and a frame advantage. All attacks can be cancelled at any point during the attack by jumping, dodging, or blocking. The cooldown of most attacks can also be cancelled by moving. Players have one attack which knocks back all enemies around them to create space. Players also have one attack to knock enemies into the air. In the air, players stop falling while attacking and hit stun also prevents enemies from falling. Additionally players have a move to get close to enemies, which can also be used to stay longer in the air. For defensive options, players are able to block and dodge. Multiple enemy attacks can be blocked simultaneously, and attacks which break through the players block are slow and have clear tells. Enemies don’t have any grabs at their disposal. By dodging players can move themselves outside the fight for a short period; until the enemies reach the player again. All enemy attacks are interrupted when they get hit. Players have one ranged weapon with a regular attack and a charged attack. The ranged weapon has a regular attack and a charge attack. It has auto targeting and the target is indicated during the charging. The player also has a special attack, which uses charges, dealing damage to all enemies around the player and consisting of invincibility frames. The player character is controlled using the general controls. Players will have a decent leeway in timing their input right.

MEDIUM A medium combat experience adds to the complexity and is intended to oppose some challenge to the players while still being accessible. Players have several moves at their disposal, with a wider variety of purposes. Most moves will have a short anticipation, while the heavy damaging moves will have a longer one. The hitboxes are slightly bigger than the weapons. Most moves give the player a frame advantage, with the exception of the heavy damaging moves. The cooldown of each attack can be cancelled by the next attack in the move, dodging, blocking, and jumping. For some moves the anticipation can also be cancelled by blocking or dodging. Players can also launch enemies into the air. In the air the player won’t have any falling speed while attacking, and enemies won’t have any while in hit stun. The knockback varies per attack, with a few strong attacks having a high knockback. Most enemy attacks can be interrupted, with the exception of the special attack of a few enemies. Players are able to block and dodge enemy attacks. The dodge is a short distance dodge which also allows players to quickly move around during the fight. The blocking blocks all attacks from all directions simultaneously. Some enemies will have attacks, with clear tells, which can break through, while other enemies will have grabs. Players will have a few ranged weapons at their disposal, from which they can only equip one at a time. Each ranged weapon has one attack and its own use. All of them can also be used during combos. Players also have a few special attacks they can choose from, with only one equipped at a time. These special attacks use charges. Each attack has its own use, while all of them render the player invincible during execution. The player character is controlled using the general controls. There is a short input buffer, yet it still gives players a some leeway on their timing.

HARD

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A hard combat experience is intended to challenge the players to get as much out of it as they can. Players have many moves at their disposal, each with specific purposes. The combat focuses around performing combos to deal damage. The anticipation, hit frames, and cooldown of the attacks vary greatly and are specific to its purpose. Some attacks will focus on quick hitting, thus have a short anticipation, while other attacks will be more damaging. Attacks can only be cancelled by the next attack in the move. In case they are the last or only attack in a move, they can’t be cancelled. The hitboxes will equal to the size of the weapon, not bigger nor smaller. Hit stun and knockback also vary greatly between different attacks; a some moves will give the player a frame advantage, which can be used to start combos, while other moves will give the player a frame disadvantage and are better to only use in combos. Only the heavy damaging moves will knock back enemies. Players will also have attacks which can be performed in the air, yet these are mainly used during combos. In the air the player´s falling speed reduces while they attacks, the same goes for enemies during hit stun. Most enemies will have attacks which cannot be interrupted by the player. The player will only be able to dodge to avoid damage. This is a short range dodge which allows the player to quickly move around through the battle. The player will also have a few ranged weapons at their disposal. Each will have one move, and its own use during combos. Players also have a strong special attack which will deal heavy damage to one enemy in front of the player. The special attack consumes one charge per use. The player character is controlled using the general controls with a small modification to use the different ranged weapons. Players will have to be precise on their timing and input as the input buffer is short.

IMPLEMENTATION These three complexities can best be implemented in a single game in the form of different weapons. This gives players the ability to choose what they want according to their preferences and playstyle. Each weapon should have a visual indication of how complex it is to inform the player what they can expect. Players should be able to freely switch between different weapons throughout the game, and be able to learn to play with all of them if they desire. Each weapon can also be designed around a specific playstyle. Keep in mind that the number of weapons isn’t limited to these different complexities.

CONCLUSION In this paper I explained how complexity is build up in combat design of hack ‘n slash games. To research this I analyzed three hack ‘n slash games; God of War 3, Ninja Gaiden 2, and DmC Devil May Cry. I also explained how the complexity can be increased or decreased per component. I advice against some of these, such as removing special effects, while others are very effective, such as move cancelling and the defensive options. I discussed how different levels of complexity can be implemented within the same game. With the best option being multiple weapons with varying complexities. At the end I’ve given a solution with a good example of an easy, medium, and hard combat experience. All this can be utilized to design hack ‘n slash with a specific, or varying, complexity. However, this isn’t limited to hack ‘n slash games. It can be used for any game which uses melee combat in a similar way. Do keep in mind that the less focus on the combat, the less complex it should be as players will be spending less time to learn it.

2013 19 by Bart Vossen

SOURCES

GAMES: - God of War 3; by SCE Santa Monica Studio, released on Playstation 3 March 2010. - Ninja Gaiden 2; Team Ninja, released on Xbox 360 June 2008. - DmC Devil May Cry; by Ninja Theory, released on Playstation 3, Xbox 360, and PC January

2013.

IMAGE SOURCES: God of war 3

- http://media.psu.com/media/wallpapers/God%20of%20War%20III%20wallpaper.jpg - http://www.thinkdigit.com/FCKeditor/uploads/l-gow3-screen1.jpg - http://onevideogamersview.files.wordpress.com/2012/06/god-of-

war3.jpg?w=320&h=260 - http://www.gamersmint.com/wp-content/uploads/2010/03/22.jpg - http://guides.gamepressure.com/godofwarascension/gfx/word/620283156.png

Ninja Gaiden 2 - http://www.onlytoptens.com/wp-content/uploads/2011/07/top-10-xbox-360-games-

ninja-gaiden-2.jpg - http://images5.fanpop.com/image/photos/24800000/New-pics-in-NG3-ninja-gaiden-

24846289-1920-1080.jpg - http://img13.imageshack.us/img13/4510/ryuhealthbarng2.jpg - http://www.ps3attitude.com/wp-content/uploads/2009/09/ngs2_controls.PNG

DmC Devil May Cry - https://s3.amazonaws.com/launchgram/static/img/RelatedProductImages/dmc-devil-

may-cry/dmc-devil-may-cry-box-art.jpg - http://leviathyn.com/wp-content/uploads/2013/01/dmc2.jpg - http://i.imgur.com/rcJOW.jpg

Other - http://aztez.com/wp-content/uploads/2012/05/Amalur-Problem-A.jpg - http://media.eventhubs.com/images/2011/01/31_blog04.jpg