> For the complete documentation index, see [llms.txt](https://axiomemu.gitbook.io/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://axiomemu.gitbook.io/docs/data/monster/monsteraiunit.md). # MonsterAIUnit AI personality glue. Each Unit picks one Automata (state machine) and maps each of the 8 AI states to an Element (the action to perform). Groups and rules reference Units by `Number`. ## File Location ``` Data/Monster/MonsterAIUnit.xml ``` Loaded once at GameServer startup. Changes require a restart. ## Dependencies | Depends On | Purpose | | ---------------------------------------------------------------- | ------------------------------------------------------- | | [MonsterAIAutomata.xml](/docs/data/monster/monsteraiautomata.md) | Supplies the state machine referenced by `Automata` | | [MonsterAIElement.xml](/docs/data/monster/monsteraielement.md) | Supplies the per-state actions referenced by `Element*` | | Used By | Purpose | | ---------------------------------------------------------- | ------------------------------------------------------------------ | | [MonsterAIGroup.xml](/docs/data/monster/monsteraigroup.md) | Assigns Units to monsters via `StartAI` / `AI01` / `AI02` / `AI03` | | [MonsterAIRule.xml](/docs/data/monster/monsterairule.md) | Temporarily overrides a monster class's Unit on a schedule | ## Role in the AI Hierarchy ``` MonsterAIGroup.xml (BasicAI per monster) | v MonsterAIUnit.xml <-- this file (picks Automata + maps states -> Elements) | +-> MonsterAIAutomata.xml (state machine) +-> MonsterAIElement.xml (actions) ``` ## Attributes ```xml ``` | Attribute | Type | Effect | | ---------------- | ---------- | ------------------------------------------------------------------------------------------------------------------------------ | | `Number` | int | Unique Unit ID. Valid range 0-99. Used as the storage index, so duplicates overwrite each other | | `Name` | string | Human-readable label. Truncated at 49 characters | | `DelayTime` | ms | Minimum delay between AI dispatcher runs for monsters using this Unit. Lower = more reactive | | `Automata` | int | `Number` from [MonsterAIAutomata.xml](/docs/data/monster/monsteraiautomata.md). Required - a Unit with no Automata never ticks | | `ElementNormal` | int or `*` | Element for state 0 (NORMAL) | | `ElementMove` | int or `*` | Element for state 1 (MOVE) | | `ElementAttack` | int or `*` | Element for state 2 (ATTACK) | | `ElementHeal` | int or `*` | Element for state 3 (HEAL) | | `ElementAvoid` | int or `*` | Element for state 4 (AVOID) | | `ElementHelp` | int or `*` | Element for state 5 (HELP) | | `ElementSpecial` | int or `*` | Element for state 6 (SPECIAL) | | `ElementEvent` | int or `*` | Element for state 7 (EVENT) | All Element references resolve against the `Number` attribute in [MonsterAIElement.xml](/docs/data/monster/monsteraielement.md). Using `*` or omitting an Element attribute leaves that state unwired - if the Automata transitions to that state, no action runs and the tick no-ops. ## State-to-Element Mapping | State ID | State | Unit attribute | | -------- | ------- | ---------------- | | 0 | NORMAL | `ElementNormal` | | 1 | MOVE | `ElementMove` | | 2 | ATTACK | `ElementAttack` | | 3 | HEAL | `ElementHeal` | | 4 | AVOID | `ElementAvoid` | | 5 | HELP | `ElementHelp` | | 6 | SPECIAL | `ElementSpecial` | | 7 | EVENT | `ElementEvent` | Each tick the Automata picks a transition; the Element bound to that transition's next state runs. The engine does not validate that the Element's declared class matches the state - an `ElementAttack` can point at a HEAL-class Element and the engine will still execute it, just as the wrong thing. ## Tick Timing Two delays gate every AI tick for a monster: * The Unit's `DelayTime` (this file) caps how often the Automata is consulted. * The Element returned by the Automata can set its own per-element delay on the monster, applied before the next Automata run. Both are in milliseconds. Lower values increase CPU load for the class. ## Cross-File References | Attribute | Resolved Against | | ---------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `Number` | [MonsterAIGroup.xml](/docs/data/monster/monsteraigroup.md) `StartAI` / `AI01` / `AI02` / `AI03`, and [MonsterAIRule.xml](/docs/data/monster/monsterairule.md) `Unit` | | `Automata` | [MonsterAIAutomata.xml](/docs/data/monster/monsteraiautomata.md) `Number` | | `Element*` | [MonsterAIElement.xml](/docs/data/monster/monsteraielement.md) `Number` | ## Common Issues * Monster idle forever - `ElementNormal` is wired but the Automata never transitions to any other state, so the non-idle Elements never run. * Wrong action in the wrong state - Element class does not match the slot. The engine executes whatever it is bound to. * `DelayTime` too low - the dispatcher runs faster than the monster's animation or path can complete, producing jerky behaviour. * AI change event does nothing - `ElementEvent` is missing or set to `*`; state 7 transitions fire but no action runs. * Duplicate `Number` - the later entry overwrites the earlier one silently. * `Number` outside 0-99 - entry is dropped silently at load. ## Related Systems * [MonsterAIAutomata.xml](/docs/data/monster/monsteraiautomata.md) - state machine that drives transitions * [MonsterAIElement.xml](/docs/data/monster/monsteraielement.md) - per-state action definitions * [MonsterAIGroup.xml](/docs/data/monster/monsteraigroup.md) - assigns Units to individual monsters * [MonsterAIRule.xml](/docs/data/monster/monsterairule.md) - time-scheduled Unit overrides * [Monster.xml](/docs/data/monster/monster.md) - monster stats and base combat parameters