The term CPU (short for 'Central Processing Unit') in the context of video games refers to elements (such as characters or enemies) whose behavior is controlled by processes programmed into the game itself. More specifically however, it is used to refer to secondary players who have been set to be controlled by the game itself, rather than any human player.
In the Kirby series, CPU players (also referred to as Computer Players, or CP in short in Japanese) can be set in any multiplayer title to stand in for real human opponents, and they are programmed to simulate how said human opponents would play to a certain degree.
CPUs often come with difficulty settings as well which the player can set to make them more or less of a challenge. The change in difficulty usually alters how quickly the CPU can react to a given situation, and whether or not they will perform certain behaviors (an example being the CPU players in Kirby Battle Royale, who are programmed to actively pick up their downed opponents and toss them into hazards at higher levels).
In every game in the series, common enemies are controlled at least to some extent by CPU programming. However, these behaviors are usually quite simple, amounting to little more than holding still, jumping in place, attacking in fixed intervals, or pursuing Kirby. CPU players - on the other hand - are typically given much more advanced algorithms and conditions which will cause them to behave in more complex manners, in an attempt to simulate strategic human play. Given the imperfect (and simplistic) nature of this programming, however, CPU players often have trouble in certain situations, and can be locked in endless behavior loops which get them nowhere.
CPU by Title
Kirby Super Star / Kirby Super Star Ultra
The Helpers in Kirby Super Star and Kirby Super Star Ultra are controlled by the CPU when not controlled by a second player. These CPU Helpers have more sophisticated behavior when compared to common enemies or bosses, most of which operate on a pre-determined set of patterns. This allows the CPU Helper to follow Kirby and help him battle enemies. In some cases, they can also help solve certain puzzles, with a prime example being Burning Leo's tendency to light Fuses that are nearby. The CPU can pick up food items and Invincible Candy, and will move toward Kirby to share them via Face-to-Face, though this is just a side effect of the normal CPU tendency to get close to Kirby, and it will not prioritize this over attacking enemies.
Under normal circumstances, the CPU Helper will approach Kirby and stand close by when he is not moving. The CPU will not be prompted to follow Kirby until he gets a small distance away. When Kirby is in the air, the CPU will generally not follow him up there, preferring to just keep underneath him on the ground, unless the environment prompts it to. Once this happens, the CPU will use its Infinity Jump to continually keep close to Kirby when he is in the air. Certain terrain, particularly tight passages, may confuse the CPU, making it unable to properly follow Kirby (shown in image).
When an enemy is nearby, the CPU will attempt to navigate towards it and attack it, with the type of attack depending on whether the CPU or the enemy is in the air or on the ground, though this can often lead to the CPU crashing into the enemy and taking damage if the path is complicated or if the enemy is moving rapidly. The CPU may alternatively choose to guard, though it rarely holds its guard for long. The CPU's attack options are performed on a timer when choosing between multiple targets, with noticeable pauses between attacks or guards in these instances. In certain situations, the CPU may have difficulty deciding whether to follow Kirby or attack an enemy, so it will run back and forth between the two objectives fruitlessly until the situation changes. When enemy projectiles are approaching, the CPU will either attempt to guard or attack it as if it were an enemy. During boss and mid-boss fights, the CPU will engage the enemy from any position, rather than having to get up close first.
The CPU will not attempt to break blocks, activate switches, or use ladders. The CPU will also not attempt to avoid hazards such as Gordos or spike pits, which can lead to situations where it continually stands on or in the path of such hazards until it is defeated. When the CPU is out of health, it will no longer try to follow Kirby around (unless Kirby gets sufficiently far away) or attack enemies, instead holding in place until it pops out of existence. If prompted to move in this state, the CPU will run frantically around Kirby once it reaches him until it pops.
Kirby's Dream Land 3
In Kirby's Dream Land 3, Kirby can call on Gooey to help him, with the cost of some stamina. When not controlled by a second player, Gooey is controlled by the CPU. Like the Helpers in Kirby Super Star, Gooey will generally attempt to stay close to Kirby and attack nearby threats, possessing almost all of Kirby's moves. Unlike Helpers, however, Gooey's CPU is much more oriented around mimicking Kirby's actions when there are no other considerations on screen. For instance, if Kirby performs a basic action such as jumping, inhaling, crouching, or sliding, Gooey will usually mimic him after a brief moment, granted the opportunity to do so. This includes walking itself, since if Kirby only steps forward a small amount, Gooey will also only move forward that same distance instead of stopping at Kirby's position like the Helpers do.
Gooey's general attack strategy is to approach enemies and eat them with his tongue, and then spit them out as a Star Bullet at another enemy. Gooey will generally hold onto any enemy he has eaten until he spots another enemy to shoot at or Kirby prompts him to by attacking or crouching. Gooey will pursue enemies at greater distance than the Helpers do, but he may still end up colliding with enemies and taking damage if the environment confounds his efforts to run up and eat them. Notably, CPU Gooey will not attempt to swallow ability-granting enemies to gain an ability, despite having that capability when controlled by a player. As such, it does not appear to be possible to have CPU Gooey utilize copy abilities.
CPU Gooey will not attempt to pair up with an Animal Friend, despite having that capability when controlled by a player. When there is a food item nearby, Gooey will use his tongue to get it, and then will send half of it to Kirby as a projectile to heal him as well. Unlike the Helpers, CPU Gooey is capable of activating a Space Jump on his own initiative, and will do so if he cannot find a path to Kirby.
Kirby 64: The Crystal Shards
CPU players (here referred to as COM players) will fill in any non-human players in the Mini-Games. The difficulty chosen for the game will affect the difficulty level of the CPU opponents.
Kirby Air Ride
In this title, CPUs play a significant role, as many objectives in the Checklists require CPU participation in some form or another. the player can set the difficulty level of the CPUs prior to a race starting, which will affect their behavior and reaction time. In Air Ride and City Trial, CPU level ranges from 1 - 9, while in Top Ride, it ranges only from 1 - 5.
CPUs are generally good at handling the road in racing modes, and can be very effective in combat situations like Destruction Derby. However, particularly in City Trial, CPUs can often be seen stuck against certain walls or obstacles (a good example being the shore just north of the Electric Lounge).
Kirby & The Amazing Mirror
When playing in single player mode, the other clones of Kirby will be controlled by the CPU. They are capable of some degree of autonomous movement, but they typically do not venture far from where they are initially placed due to generally being goalless. The player can call the CPUs to Kirby's location using the Cell Phone, where they will automatically attack nearby opponents. When Kirby initiates a Super Inhale, the CPU Kirbys are programmed to recognize this, drop their abilities and join in inhaling.
Kirby: Triple Deluxe / Kirby Fighters Deluxe
In the Kirby Fighters Sub-Game, (and subsequently in Kirby Fighters Deluxe) non-human controlled opponents are controlled by the CPU, with the chosen difficulty setting determining their behavior. They are programmed to attack their opponents, attempt to dodge when being attacked, and go for items that appear.
There are five levels of difficulty for the CPU opponents, with each level having the following basic behaviors:
- Level 1: CPUs generally walk around in semi-random directions without a clear goal most of the time. They never move quickly and throw out attacks in a largely random way, often with no target. They make no attempt to avoid hazards and do not prioritize items that appear. They never dodge or guard.
- Level 2: CPUs are generally aimless when not near an opponent, but start to attack with more fervor when someone else approaches. They do run on occasion, but still cannot dodge or guard, and generally do not avoid hazards or go after items, though they do sometimes seek out food.
- Level 3: CPUs move generally quickly, and gain the ability to guard and dodge, though they only sometimes do this. They are generally aggressive and will seek out items that appear on the stage.
- Level 4: CPUs attack much faster, and make more use of attacks that give them burst or countering options. They are much more likely to dodge, particularly when it comes to projectiles.
- Level 5: CPUs gain near-perfect dodging and guarding ability, and prioritize items with maximum speed. They constantly attack opponents when they are close.
Kirby: Planet Robobot, Team Kirby Clash Deluxe & Super Kirby Clash
In the trio of games Team Kirby Clash, Team Kirby Clash Deluxe, and Super Kirby Clash, non-human controlled teammates and adventurers are controlled by the CPU. They will attempt to fight the enemy, pick up Power Tablets and Food, and revive fallen comrades. They will also attempt to dodge certain attacks which the enemy throws out, though not always with success.
A couple specific notable behaviors of the CPU include the following:
- When they are near an item such as food or a Team Meteor Power Tablet and are in need of it, they will prioritize it, which may lead to them running into an enemy or its attacks if those are in the way.
- The CPUs will ignore Power Tablets if a Time Beam is active, as activating a Team Meteor cancels out the Time Beam.
- When the player's Kirby is KO'd and calls out for help, teammates will prioritize reviving that Kirby, again ignoring other hazards.
- Whenever a piece of food is picked up, or Doctor Healmore uses his Science Lab to drink a stamina potion, CPU teammates who are low on stamina will prioritize approaching the Kirby who just used the item and receive a Face-to-Face. CPU teammates who use recovery items will also prioritize approaching wounded allies for this same purpose. They will also prioritize recovering lost stamina by running into Healing Areas, once again ignoring enemy attacks.
- When a CPU teammate is within collision range of an enemy or attack, they will attempt to hold a Guard until this is no longer the case. This can be an issue, as CPU teammates may end up breaking their own guard and becoming dazed, or may be guarding at times when it is more appropriate to dodge or attack.
- CPU teammates are automatically programmed to take specific dodging action for certain moves, such as Pyribbit's fire breath, but do not know how to dodge other attacks such as Aeon Hero's energy sword rain attacks.
- CPU teammates are programmed to charge their special attacks under certain circumstances, such as during invulnerability transitions of enemies, but are not inclined to hold the charge until the enemy is vulnerable again, instead insisting on releasing the attack as soon as the charge is complete. This often results in the teammate whiffing the attack.
- In addition, CPU teammates will almost always insist on fully charging their attacks, and will often not release them early, even when it is advantageous to do so.
- During the Team Meteor meter, CPU teammates will generally follow the player's result, though they may deviate somewhat. As such, it is rare to get a perfect result when playing solo.
Kirby Battle Royale
CPU opponents can be set in Battle Mode, and are also encountered in Dedede's Cake Royale. In Battle Mode, their difficulty can be set between levels 1 - 5. Each different battle mode necessitates different behaviors on part of the CPU opponents, but higher levels generally involve becoming more aggressive as well as giving more priority to the actual objective of the game in question, whether that be simply defeating opponents, collecting items, or going after opponents who have larger scores or stacks of items than others.
The following is a quick rundown of what can be expected of CPU opponents at each level of difficulty:
- Level 1: CPUs waddle about slowly, often in random directions. Occasionally, they throw out an attack in the direction of an opponent. They are capable of bouncing back from being knocked down on occasion, but they do not use charge attacks outside of the specific objective in Crazy Theater. They will not attempt to pick up downed opponents. In teams, these CPUS may attempt to fruitlessly attack each-other. In Crazy Theater, they are likely to stand on the wrong answer in certain panel challenges. In other game modes like Apple Scramble or Rocket Rumble, they will not attempt to sabotage the opposing players.
- Level 2: CPUs place slightly higher priority on the objective of the round, but are still largely aimless outside of plain fighting. Additionally, they will occasionally toss items at opponents to knock them down. They throw out attacks more frequently, and will make some effort to sabotage opponents instead of just trying to attack them. They still do not typically use charge attacks or pick up downed opponents.
- Level 3: CPUs will start to use charge attacks at this level. Their attacks also become more focused and frequent, they become better at dodging, and they recover more often from being knocked down. They still do not have much sense of objective during games like Rocket Rumble, however.
- Level 4: CPUs are more inclined to use items to knock opponents down, and will make a greater attempt to guard important resources and objectives, particularly in games like Crazy Theater and Flagball. They are more inclined to fight in a defensive manner than lower level CPUs, waiting for openings to attack. They are also more likely to make use of charge attacks outside of Battle Arena.
- Level 5: CPUs start to "play dirty" at this level, making much more of an effort to sabotage opponents. In particular, they will pick up downed opponents and toss them directly into hazards, which is most notable in games like Crazy Theater.
Kirby Star Allies
The Friends and Dream Friends which Kirby can recruit can be controlled by the CPU, in addition to human actors. When controlled by a CPU, their behavior is similar to how helpers operate in Kirby Super Star, though they will generally prefer to keep behind Kirby. When Kirby requests a Friend Ability combo, any compatible friend will be alerted to this, and use their ability; if one friend provides multiple combos or there are multiple friends who can provide different combos, they will be performed one after the other as long as Kirby continues to request them. If no compatible friend is present, they will simply display question marks (?) instead and do nothing. In addition, Friends will interact with objects in specific ways in response to Kirby's actions. An example of this is when Kirby hops in a fuse cannon - a friend with a fire-type move will be prompted to go and light the fuse.
The sophistication of the CPU friends in Kirby Star Allies is notable, as they can often be seen attempting to avoid hazards and have decent pathfinding. However, in complicated environments, they can still have difficulty maneuvering, and in some cases, may end up avoiding one hazard only to run into another repeatedly. This is particularly notable in the rare Picture Piece room on Sizzlai Moon, where falling meteors prompt CPU allies to run away, but they may end up repeatedly running into and getting hurt by the lava floor to the right (or accidentally jumping into another meteor) in their attempt to escape. The crushers in The Divine Terminus are another hazard which friends commonly have difficulty avoiding.
Kirby Fighters 2
The CPU-controlled opponents in Kirby Fighters 2 are similar to those in the previous two Fighters games. When controlling each character, the CPU has a tendency to attempt to utilize those fighters' specific attacks in the way they were intended, with examples including Bell Kirby making frequent use of the Bell Block guard, Archer Kirby shooting from a distance whenever possible, and Water Kirby keeping opponents at bay with the Wave Attack and using Fountain Hover when above an opponent.
As before, CPU difficulty ranges in standard battles from levels 1-5, though more specific levels on a different scale from 1-50 can be found in the Story Mode: The Destined Rivals. Lower level opponents tend to move slowly and rarely attack or guard, while higher level opponents frequently block with perfect precision and always move as fast as they can. CPUs will also tend to Gobble or grab whenever they are up close to an opponent and will prioritize items whenever they appear on stage. Whenever a CPU picks up an item that can be shared with a teammate using Face-to-Face, they will prioritize doing that above all else. The CPU will also attempt to make their way back to the player if the player's character picks up such an item. The same general rules apply when picking up the pieces of the Buddy Star Blaster. Lastly, if the player has used a Gobble or Grab on an opponent, a teammate will attempt to position themselves in order to hit that opponent when he is thrown.
A few significant flaws can be noted with the CPU behavior however. When an opponent has Invincible Candy active, for instance, CPUs will not adjust to this, and will continue trying to attack that opponent as if they were still vulnerable. It is also possible, with certain techniques, to trap a high-level CPU in a corner and use the same attack repeatedly on them, and they will be unable to escape or counterattack, instead opting to occasionally guard or dodge in place as they are gradually defeated. Additionally, while the CPU has its aforementioned ability to guard or dodge with perfect precision, it does not have the ability to anticipate attacks coming their way, meaning it is still possible to defeat them easily by repeatedly using the same move at a distance. Lastly, it is possible in certain instances for CPU opponents to be compelled to hold their Guard for too long and end up breaking it, becoming dazed. This is particularly notable with the CPU buddy in Story Mode: The Destined Rivals, while fighting bosses.
List of adjectives
In Kirby Fighters 2, CPU-controlled opponents in Story Mode: The Destined Rivals and Single-Handed Mode have adjectives attached to their names based on their relative level from 1-50. The following lists off every known prefix in the game by level (note that some level numbers are skipped due to those not showing up specifically in the Story Mode):
- Level 1 - 3: Adorable, Beginner, Bumbling, Caring, Chatty, Childish, Clownish, Cutesy, Dewy-Eyed, Doughy, Dreaming, Famished, Fresh-Faced, Gentle, Half-Baked, Hungry, Laid-Back, Newcomer, Novice, Ordinary, Pillowy, Reckless, Refreshing, Romantic, Scared, Softhearted, Taciturn, Young, Youthful
- Level 5 - 8: Big-Hearted, Cool, Daydreaming, Dulcet, Fetching, Gale-Strength, Ghostly, Gourmet, Graceful, Guileless, Heartfelt, Honest, Jolly, Mysterious, Polite, Puffy, Radical, Rash, Roaming, Sleek, Solemn, Trendy, Vain, Wild
- Level 12 - 17: Boisterous, Bold, Chipper, Competitive, Developing, Fearsome, Flawless, Furious, Great, Hardworking, Omniscient, Perky, Powerful, Professional, Resilient, Rising Star, Serious, Shrewd, Stubborn, Sturdy
- Level 22 - 27: Acclaimed, Brilliant, Classic, Disciplined, Elite, Empyrean, Exceptional, Extraordinary, Fearless, Flaming, Gentlemanly, Historical, Lost, Merciless, Outstanding, Reborn, Revived, Seasoned, Traveling, Unrestrained, Wandering
- Level 30 - 34: Afar-Returned, Balletic, Dangerous, Destroying, Divine, Fake, Grand, Hardened, Juggernaut, Legendary, Loyal, Ominous, Revenging, Stormy, Supreme, Terrifying, Undefeatable
- Level 40 - 50: Aeon, Ally, Breezy, Daredevil, Far-Flung Star, Galaxy-Ruling, Heroic, Master, Mighty, Rainbow, Soulful, Star Monarch, Super-Deluxe, Ultimate, Ultra