This page contains information about an element of Guild Wars that has changed as of the February 05, 2019 update, and may need to be updated due to the following reason: Updated the AI for Heroes, Henchmen, and monsters for some skills.
Detailed analysis of hero skill usage (and lack of) can be found at Hero behavior/Unexpected behavior. See here for a list of skills with documented hero usage.
AI capabilities and limitations
Heroes are like "toddlers": give them skills that are effectively impossible to use incorrectly, or skills that focus on a single target without conditional secondary effects. While they can "auto-pilot" their way through enemies with the correct skills, they do so less effectively than a human team might. When using heroes, calling targets and directing them will always increase their efficiency. Fortunately, the list of fail-safe skills is sufficient enough to create an effective hard mode set-up.
Customized hero builds take full advantage of the AI's superior reaction time and field awareness (for interrupts, spreading hexes, certain prots) while avoiding AI disadvantages (inability to use certain skills, lack of planning ability, not understanding positioning).
- Heroes can "read" health bars, and can detect the presence of hexes, conditions and enchantments.
- Heroes know about all active effects. They will not try to apply an enchantment, hex, condition or weapon spell on someone who is already affected by the same enchantment, hex, condition or weapon spell.
- Heroes can detect party members' energy, as they will not use skills such as Blood Ritual on characters with full energy pools.
- Heroes can detect enemy skill activation, and will only use interrupts which are appropriate to the skill type. They have no reaction time; their interrupts are never late.
- Heroes seem to mimic players' reaction times, such as activating skills for which the condition is met just before activation, but removed before the skill can take effect.
Heroes do not coordinate their actions with each other. This may result in redundant skill usage. For example:
- Multiple heroes with resurrection skills may attempt to resurrect the same fallen party member; the fastest one will succeed (unless interrupted), which means the others will have wasted energy and time.
- Multiple heroes may try to heal the same ally, even if it's almost at full health, or damage the same foe, even if it's almost dead.
- They may try to remove the same hex, condition, or enchantment. They may try to interrupt the same skill.
- Heroes have no concept of the danger of hexes and conditions, or the usefulness of enchantments. They will remove these seemingly at random.
- Heroes have no concept of the strength of a skill. They will not prioritize any skills for interruption.
- For example, they may interrupt Flare while allowing Meteor Shower to be cast. They will not prioritize the interruption of resurrection skills.
- All heroes with resurrection skills will attempt to resurrect fallen party members; the fastest one will succeed (unless interrupted), which means the others will have wasted energy and time.
- Healers often attempt to resurrect in mid-combat. Players that want their healers to focus on healing should give resurrection skills to non-healers, or manually disable the healer's resurrection skills to reserve them for the player's discretion.
- Unyielding Aura, however, is a fantastic resurrection skill for a hero Monk, as heroes will dismiss it instantly as soon as a party member dies in its range.
Default skill usage
- See also: Category:Hero-vetted skills
- AI won't pre-cast Avatars before engaging in combat, as only the player can know when they are about to engage foes. Heroes will activate it soon after hitting their first foe. This behavior combined with the 2 second cast time could cause the hero to be interrupted. Once a battle ends, they won't re-cast it to keep it maintained between fights.
- Except for Life, AI does not use passive spirits outside of combat. Spirits like Union will only be cast after a party member has already taken damage, but never to prevent that first strike.
- AI will place spirits wherever they happen to be, it is not programmed to make spirit walls as players would. Additionally, it will use skills like Armor of Unfeeling, Signet of Creation, Signet of Ghostly Might, Spiritleech Aura once it detects the presence of a single spirit within range.
- NPCs will try to cleanse allies of conditions, even if those conditions are about to wear off. This both wastes energy and delays party movement.
- They are better at detecting conditions than humans, who need to watch health bars or wait for other players to ping their effects (or mention them via chat).
- They will remove conditions on allies even when the other NPC would benefit from the condition, e.g. under the effect of Melandru's Resilience, or when unavoidable e.g. Cultist's Fervor.
- NPCs do not spread conditions. For example, while Apply Poison is active, they will not attack multiple targets to poison several foes. Worse, they will cease attacking poisoned foes if that preparation is active.
- Heroes seem to use Echo or Arcane Echo early on during a fight, after which they will use a random skill without having a thought of what skill will be echoed.
- NPCs will always cast all available elemental attunements, as well as Aura of Restoration, regardless of attribute rank in a particular magic and equipped weapon.
- Battery skills
- NPCs will only use Blood Ritual/Blood is Power on martial profession allies that are holding a bundle or a caster weapon; even then, they wait until energy drops to 20 or less before casting.
- They will use these skills on caster allies regardless of their weapon type, but wait to cast it until the target's energy drops to ~30 energy or less.
- NPCs will activate conjure spells based on their weapon’s current damage type, but ignore effects that change the damage (e.g. Winter or Staggering Force).
- Doublecast enchantments
- NPCs will wait to cast until foes are in range of both the caster and target ally. Unless foes are in its range, this causes the caster to close in by breaking formation. [verification requested]
- Enchantment removal
- NPCs will use maintained enchantments during combat, but dismiss them afterwards in order to regenerate energy. To force heroes to maintain such effects, you have to micromanage their usage: disable the skill (via
shift + click) and then manually cast it (by clicking on the skill). To force the hero to use a skill on a specific ally, first select the ally in the party panel, then micro the skill as above.
- Orders skills
- NPCs will wait to start casting an order until the previous application has run out, thus leaving gaps in enchantment coverage.
- After casting a glyph, NPCs will prioritize skills optimized to the specified effect. For example:
- After invoking a Glyph of Lesser Energy, they will often ignore spells that cost only 5 in favor of those costing 15 or more.
- After invoking a Glyph of Swiftness, they will use skills indiscriminately.
Healing and protection
- NPCs reserve party-wide healing skills (e.g. Heal Party) until multiple party members require healing.
- They prioritize the ally with the lowest health and will not protect goal-critical non-party NPCs (e.g. Prince Rurik or Master Togo). Players can micromanage this by targeting the non-party NPC and manually activating a healing skill.
- They cast hex-removal skills indiscriminately, regardless of danger level or remaining duration.
- NPCs will detect near-death allies and prioritize their healing.
- They will also apply special-circumstances skills appropriately, e.g. Divine Intervention.
- However, they will sometimes cast skills with effects-on-death first, notably Death Nova.
- NPCs will not use protection skills in advance of a battle; players must micromanage pre-casting of skills such as Shelter.
- NPCs will not use protection skills if the NPC itself is not in aggro range of an enemy or receiving damage from within casting range. NPCs that are flagged on the peripheral of combat yet not within range of opponents will never use protection skills, even if party members are within effect range of their skills and dying.
- When allies are suffering from health degeneration, NPCs will use skills that reduce direct damage to no effect, for example casting Spirit Bond to counter Conjure Nightmare.
- NPCs will first use resurrection skills on dead allies that also posses resurrection skills.
- Multiple NPCs will attempt to resurrect the same ally.
- NPCs prioritize cleansing over other considerations:
- They will remove minor hexes from allies that might enjoy a net benefit, e.g. removing Overload from a target under the effects of Resilient Weapon.
- After a battle is over, NPCs will take time to remove hexes (regardless of danger level), resulting in them being separated from the rest of the party. This makes it more difficult to avoid other foes in the area or along the party's route.
- Mesmer hex removal
- Shatter Delusions / Drain Delusions - heroes will use these regardless of mesmer hexes that have an effect upon ending,
- NPCs do not prioritize threat levels. They will interrupt Flare on a current enemy even if a nearby foe is casting Rodgort's Invocation.
- Skills that interrupt will often be postponed in use as long as the target's "skill activation window" is still visible.
- AI seems to be vastly superior to players in terms of interruption time, suggesting an uneven split of replicating player intelligence
- Heroes will try to maintain defensive item spells when out of combat. They will attempt to follow foes when other allies are attacking. They will not drop item spells that cause offensive effects to use other offensive item spells.
- Heroes will try to keep Beast Mastery and Wilderness Survival spirits active at all times. Favorable Winds will only be used when in combat.
- NPCs maintain preparations outside of combat, even if no combat is imminent.
- NPCs will prioritize the use of shadow steps to close the distance to foes, sometimes ignoring or wasting the secondary effects. However, they will use Death's Charge to heal themselves while in melee range of their target.
- They will use shadow steps differently on different types of targets. For example, on the Isle of the Nameless, heroes will use Death's Charge to step to the Master of Healing (a non-offensive build) but walk/run to the Master of Lightning (an offensive build) and reserve Death's Charge as a self-heal.
- After using a shadow step, NPCs will sometimes walk away from a foe (and back towards the party).
- Heroes will only use shouts when in combat.
- Except for Speed boost shouts (e.g.:"Incoming!", "Fall Back!", "Make Haste!").
- They will only use "Make Haste!" on player characters and never on NPC allies.
- NPCs will use AoE spells on single targets, e.g. Fireball against an animal.
- To maximize the effects of use of Point-Blank AOE damage skills, they will rush into combat, even if the rest of their build is not suited for close-combat. In particular, they will not reserve PBAoE skills to break aggro, e.g. they will also move close to foes to use Whirlwind, rather than using it to escape from that same foe.
- Dervish skills such as Wearying Strike that remove a dervish enchantment to trigger an additional effect or avoid a penalty will be used regardless of whether any dervish enchantments are active.
- When enchantments are available, they will not distinguish between enchantments meant to be removed in this manner and enchantments that are meant to be maintained.
- NPCs with martial professions use touch skills efficiently, since they are already face to face. However, casters will break formation, rushing into to the frontline to cast such skills, risking their own safety. For example, Danika will use Healing Touch instead of remaining safely behind.
Wards and Wells
- NPCs will invoke Wards and Wells when engaged in combat, regardless of the benefits. For example, they will cast Ward of Stability even if there is no risk of knock down.
- They do not pay attention to existing areas of effect, moving outside of beneficial effects to kite or remain within negative ones if they are not under direct attack.
- After the end of a battle, NPCs with both minion and well skills sometimes choose to invoke wells (even if they serve no purpose) instead of creating more minions.
- NPCs will cast offensive weapon spells on attacking allies appropriately, e.g. using Splinter Weapon on allies wielding martial weapons.
- However, they will overwrite those skills with supportive ones, especially on allies at critical health levels. For example, they will use Weapon of Warding, even if they just used Splinter Weapon on the same target.