Artificial Intelligence
Artificial Intelligence is a series feature in which party members are controlled by the game itself instead of the player, emphasizing the individuality of cast of characters as well greatly expediting the rhythm of battles.
A ground-breaking innovation created by Chunsoft employee Manabu Yamana, the developers of each following game listened closely to player feedback when programming the next entry, studying the ways players react to situations and incorporating intentional quirks to gradually perfect the A.I. to become the most sophisticated simulation of human behavior in the video game industry.
Overview[edit]
Artificial intelligence in Dragon Quest is a derived evaluation function based on a hidden "fear" stat possessed by each monster, which represents how dangerous a monster is from the character's point of view.
A monster's fear stat is based on the numerical value of damaging abilities such as regular attacks or spells such as Frizz, with status ailment inducing abilities also being given "damage" values for the sake of a thorough threat assessment. Monsters that can heal or revive an ally have the fear stat of all other monsters added to their own because they can drag the fight out longer than necessary. Once every individual monsters' fear stat has been calculated a special consideration will be made if a monster can be defeated with a single attack, as this will reduce the overall fear stat the quickest; if no such monster is present on a given turn then priority returns to the monster with the highest fear stat.
Once the fear assessment is made a character will attempt to act in the most efficient way to eliminate the most dangerous monster with the options he or she has available, further influenced by the battle tactics set for the party. These decision calculations are conducted at the start of a character's turn to allow the A.I. to react to the changing circumstances of a battle, and the most common tactic options in the series are as follows:
| Tactic | Description |
|---|---|
| Fight Wisely | Defeat the enemy in an efficient manner that is MP-conscious |
| Show No Mercy | Defeat the enemy as quickly as possible with no concern for MP |
| Focus On Healing | HP recovery is given the priority |
| Watch My Back | Focuses on buffing allies and using the defend command instead of attacking |
| Don't Use Magic | No spells are ever used |
| Follow Orders | The player directly controls the character |
For healing the A.I. considers the HP threshold of the characters and compares that to the MP conservation guidelines set by the current strategy, with the "Focus On Healing" strategy having the highest HP thresholds to maintain and the lowest MP thresholds; I. E. healing is preformed when only a comparatively small amount of HP is lost with no regards to conserving MP. Special consideration is given to characters that can reduced the fear stat sum by the most on a given turn: for example if Alena and Borya both have 1 HP but Alena has Oomph cast on her and Borya has zero MP left then healing priority will be given to Alena because she is currently the most useful character that needs healing.
Appearances[edit]
Dragon Quest III: The Seeds of Salvation[edit]
A.I. was first implemented in 2014 with the release of the Android/iOS version. The program is more simple compared to other games released around the same period and in some ways is dumber than the A.I. written for the original version of Dragon Quest IV. For example monster resistance is based on success probability like status ailment spells instead of using the damage reduction formula standard set by Dragon Quest V, meaning that the A.I. only considers the possible damage output and might cast Kaboom in situations where all enemies have a 75% chance to take no damage at all.
An exceptional instance of bad A.I. can be found in the basement of the pyramid, where all magic is sealed away. A.I. controlled characters are oblivious of the pharaoh's curse and will attempt to cast spells anyway, wasting their turn until the player takes control or the Don't Use Magic tactic is set.
Dragon Quest III HD-2D Remake[edit]
The A.I. is much more sophisticated to the one seen in the Android/iOS version, and characters will not waste turns trying to use spells in the basement of the pyramid. The decision-making is finely-tuned in regards to conserving MP and reusable items such as the stormlord's sword are given a high priority.
The Hero can also be controlled via A.I. now, following the series trend set by the Nintendo 3DS port of Dragon Quest VIII in 2015.
Dragon Quest IV: Chapters of the Chosen[edit]
Artificial intelligence was given the utmost priority during the initial planning meeting for Dragon Quest IV in February of 1988, with the finer details being decided upon during subsequent meetings until the list was finalized by June. Programming the A.I. was done by Manabu Yamana over the course of approximately one year.
Characters are initially ignorant of the resistances of any given monster but become aware of these aspects the longer a monster is fought, influencing the decision making of the A.I. that is shared between them. Time is measured in turns and every turn has a chance for the A.I. to level up and learn more of a monster's resistances, gaining total awareness at level 3.
| Awareness stage | Level up probability |
|---|---|
| Level 0 → 1 | 255/256 |
| Level 1 → 2 | 1/2 |
| Level 2 → 3 | 1/4 |
Clever players can make use of the Kaclang spell to accelerate the A.I.'s learning process, as well as make dumber enemies waste their own MP. Knowledge of a monster's resistances are retained once a battle is over and the information is shared by all characters, even those that remained in the wagon and did not participate. This was done at Yuji Horii's insistence as he wanted to emphasize that the cast was a group of companions travelling together who would thus naturally share tips on how to bump off foes, and also to avoid the inconvenience of having to frequently swap out the party line up.
In regards to Kiryl's infamous use of the instant-death Whack and Thwack spells against resistant monsters, this is due to the A.I. interpreting the one-hit knock out nature of the spells as high damage output instead of a success probability like with status ailment spells. This isn't so much of a problem against normal enemies as the learning method of the A.I. will eventually correct the misguided priest's judgement, but monsters that can shift between different phases such as the winky are treated as being new foes by the A.I. and Kiryl has to learn all over again. The worst instance of this is against the final boss himself, who possesses no less than seven different stages in his battle.
The six tactics in the NES version of the game are:
| Tactic | Description |
|---|---|
| Fight Wisely | Defeat the enemy in an efficient manner that is MP-conscious |
| Show No Mercy | Defeat the enemy as quickly as possible with no concern for MP |
| Focus On Healing | HP recovery is given the priority |
| Save MP | More strict on using MP than Fight Wisely |
| Don't Use Magic | No spells are ever used |
| Mix It Up | Random actions are applied, only tactic to use items |
There is no way for the player to take direct control of party in the fifth chapter of the game save through the use of a cheating device.
PSX remake[edit]
Developer Heartbeat based the A.I. off of what it created for Dragon Quest VII, released the year prior to this remake, with the player being able to assign tactics to specific characters instead of the whole party at once. Additionally the "Save MP" and "Mix It Up" tactics were replaced with the following strategies:
| Tactic | Description |
|---|---|
| Watch My Back | Focuses on buffing allies and using the defend command instead of attacking |
| Follow Orders | The player directly controls the character |
Aside from the modified tactics list the most noticeable change is the implementation of "personality" to each character's A.I., as was pioneered in Dragon Quest VII. This means that each character is programmed to favor certain actions over others even within the guidelines of a chosen battle tactic which can lead to bouts of irrational actions, a decision Horii insisted upon to better replicate human behavior. This can best be seen in Kiryl's actions when Alena is also in the party: he will always prioritize keeping her health above ~60% due to his one-sized crush on the Tsarevna. Kiryl's A.I. has also been written to favor the instant-death spells as a homage to the recurring gags that had built up around the character in word of mouth, 4koma manga, etc over the years, and due to the removal of the learning aspect of A.I. from the series as a whole in Dragon Quest VI this bad judgement will not improve over the course of the journey.
Additionally all A.I. characters no longer make use of items in battle.
DS port[edit]
The deliberately flawed A.I. has been toned down considerably over criticism of Kiryl's quirks, but the fundamental difference of the A.I. knowing an enemy's resistances from the start of battle remains.
Dragon Quest V: Hand of the Heavenly Bride[edit]
The A.I. is essentially the same as in Dragon Quest IV, with the addition of three improvements. Firstly players are now able to directly command party members as in the Erdrick Trilogy via the Follow Orders tactic, a direct response to the criticism the previous game received. Note that recruited monsters need a wisdom stat of 20 or higher before they will obey the player.
Secondly the learning A.I. is now guaranteed to have a total understanding of a monster's resistances by the third turn of battle, eliminating random chance completely. Boss battles also have been given special priority in that characters are fully aware of their attributes from the start, forgoing the possibility of wasting turns with bad decisions during what would have been the learning phase.
The third change actually applies to the battle system as a whole, which is attack spell resistance becoming damage reduction. This gives the A.I. a much firmer grasp on which attack methods are the best choice of action in a given situation as now the only way for a monster to avoid taking any spell damage is if it is immune to that spell's element.
A.I. decision making was also accelerated on the 16-bit hardware by starting calculations on the command menu instead of when it becomes the A.I. character's turn. The entirety of the process is performed as the command menu fades for the battle scene to play out, successfully masking the processing time from the player.
Two shortcomings of the game's A.I. are that disposable items are now put to use freely in any tactic, meaning that there is the possibility of medicinal herbs or rockbomb shards being wasted on small fry battles instead of being saved for bosses, and that it will never use the Defend command even if a character is in dire condition.
PS2 remake[edit]
Developer Arte Piazza built off of Heartbeat's foundation in the PSX version of Dragon Quest IV, but overemphasized the deliberately irrational behavior to the point that the A.I. is frankly unreliable. Too much priority is given to healing even with the "Show No Mercy" tactic, with monsters that know Omniheal abusing the recovery spell even if their HP has only been cut by 10% and wasting valuable MP. There is also considerable difficulty in understanding the random width of damaging spells and skills: for example if an enemy has 50 HP and an A.I. monster has the Fire Breath (40~60) and the Inferno (65~85) skills it will default to using the weaker breath attack and potentially leave the enemy alive. This is because the program improperly calculates the odds of the dealing the necessary 50 points of damage against the chance of dealing less, and does not consider using the stronger skill at all despite that being a guaranteed knock out.
DS remake[edit]
The dumbness of the PS2 version has been rectified, but the A.I. is still less efficient than the original 16-bit version. For example characters who have a raw attack power beyond a certain threshold will not use attack spells even when facing large groups. The behavior of recruited monsters with less than 20 wisdom points is also less than satisfactory, often performing sub-optimal moves or flat out wasting their turn as seen with the adolescent Sabre in the first generation.
Dragon Quest VI: Realms of Revelation[edit]
Heartbeat has taken over development duties from Chunsoft and removed the A.I.'s learning phase seen in the past two games, considering the feature to being more of a redundant novelty than an asset and freeing up precious memory space on the cartridge: character A.I. is now fully aware of a monster's resistances the moment battle begins, setting the standard for the series going forward. The competency of the A.I. now scales a character's wisdom stat, with brighter party members displaying superior cunning in battle while dumber ones fail to take advantage of their resistance knowledge.
The prevalence of skills that require no MP to use means the A.I. will typically favor muscle over magic, and the use of items has been removed altogether due to criticism of the program's cavalier attitude in the previous game. Another point of interest is that the high djinks and overkilling machine are able to take additional actions per turn just like their feral counterparts if they are controlled by the A.I., making recruiting them well worth the hassle.
DS remake[edit]
The A.I. now makes use of non-disposable items in battle, making the Staff of Ghent particularly useful in the battle against Murdaw.
Dragon Quest VII: Fragments of the Forgotten Past[edit]
Individual characters can now be assigned specific tactics for the first time, and individual characters have also been programmed with priorities to match their personalities. For instance Maribel favors attack spells in most situations unless the player has purpously trained her in melee-focused vocations.
The A.I. is still unable to make use of items as in Dragon Quest VI.
3DS remake[edit]
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Dragon Quest VIII: Journey of the Cursed King[edit]
The premier Level-5 title restores the ability to use non-disposable items in battle, becoming a fixture in all subsequent games and remakes from 2005 onward.
3DS port[edit]
The Hero is now able to be controlled by the A.I. as other characters are, a feature that would be brought forward in all subsequent games and remakes from 2015 onward. Though this creates a certain disconnect as the Hero is the avatar of the player, this method does wrap up the average battle considerably quicker.
Dragon Quest IX: Sentinels of the Starry Skies[edit]
The A.I. decision making capability is now based on a character's level, due to removal of the wisdom stat for magical might and magical mending. Disposable items are now freely used, owing to scarcity being all but eliminated thanks to the prevalence of alchemy in the game. As such, the "Mix It Up" tactic has returned after a 19 year absence.
Dragon Quest X[edit]
Due to the game's nature as a MMO the A.I. only applies to guest characters. Also owing to the game requiring a subscription to play, exceptional priority is given to metal slimes whenever one appears.
Dragon Quest XI: Echoes of an Elusive Age[edit]
The finer details of the A.I. vary between the different editions of the game.
Normal[edit]
Character personality is overemphasized once more as in the PSX version of Dragon Quest IV, to the detriment of clarity of thought in most cases; for example Jade will heavily rely on her Puff-Puff even if her charm stat is low. The party as a whole gives zero consideration to whether enemies are under the charmed status ailment, effectively wasting Jade's time.
Nintendo 3DS[edit]
The A.I. is especially MP-conscious and prefers to save points for the long haul whenever possible. For example if Veronica is facing a group of enemies that are weak to Fire and one is low on HP she will cast Frizz to finish off the single foe instead of casting Sizzle to weaken the whole group.
S:Definitive Edition[edit]
The A.I. for the game's 3D mode has been improved compared to the vanilla edition, with the personality focus being dialed down for better decision making. The A.I. for the 2D mode is imported from the Nintendo 3DS edition.
Dragon Quest Monsters 1 & Dragon Quest Monsters 2[edit]
Artificial intelligence in the first two Monsters games is based on the wisdom stat ala DQ VI through VIII, but is also influenced by the personality of the monster as well.
Decision making is based on three aspects, Bravery, Caring, and Prudence, which place emphasis on dealing damage, healing, and buffing or debuffing respectively. Each personality places a different emphasis on these three aspects and will supersede the efficiency given by the wisdom stat if the personality does not vibe with the chosen tactic. For example the Sly personality has a low emphasis on bravery and caring but a high emphasis on prudence, which means that even if the tactics are set to "Show No Mercy" the monsters with that personality will attempt to debuff the competition even in situations where doing so makes no sense.
Trivia[edit]
- One might assume that Nintendo beat Chunsoft to the punch on implementing A.I. combat in 1989's Mother, where the player is given the option to initiate an auto-battle from the command menu, but this feature does not utilize situational learning A.I., however, and simply has the cast of characters use normal attacks on enemies until the battle is won.
External links[edit]
- AI in DRAGON QUEST IV : Game AI technologies from the Two Interviews with Creators, an English interview with Manabu Yamana and Yuji Horii
