Bots

A compact recipe for adding a computer opponent. Full details in the Bots & behavior trees reference.

Minimal chaser

bots:
  - id: chaser
    name: "Chaser"
    zoneId: play_area   # home zone: spawns inside, stays inside
    count: 1            # one chaser at game start
    speedMps: 2
    tunable:
      - { key: speedMps, label: "Speed (m/s)", min: 0.5, max: 8, step: 0.5 }
      - { key: count, label: "Chasers", min: 1, max: 10, step: 1 }
    behavior:
      kind: chase_nearest

That’s a working opponent: it spawns into its home zone at game start, heads for the nearest player every tick, and the GM can slide its speed or scale the pack with the count knob.

State-driven chase/flee

Switch behavior on the bot’s own state with a selector of guarded sequences, ending in wander as a safe fallback:

behavior:
  kind: selector
  children:
    - kind: sequence
      children:
        - { kind: state_equals, key: it, value: true }
        - { kind: chase_nearest, where: { key: it, value: false } }
    - kind: sequence
      children:
        - { kind: state_equals, key: it, value: false }
        - { kind: flee_nearest, where: { key: it, value: true } }
    - { kind: wander }

Source: apps/wage-engine/src/games/tag/game.yaml. Because the bot reads the same it state humans do, your existing tag rule already controls it.

Let rules drive the bot

Trees only read state. To change a bot’s mind, write its state from a rule. Bots vs Humans flips a behavior string by health:

- id: bot_retreat_when_low
  when:
    kind: and
    children:
      - { kind: compare, who: { byTeam: red }, op: lte, left: { ref: same.state.health }, right: 30 }
      - { kind: state_equals, who: same, key: behavior, value: chase }
  do:
    - { kind: set_state, target: same, key: behavior, value: retreat }

…and the tree dispatches on behavior:

behavior:
  kind: selector
  children:
    - { kind: sequence, children: [ { kind: state_equals, key: behavior, value: chase },   { kind: chase_nearest, where: { key: human, value: true } } ] }
    - { kind: sequence, children: [ { kind: state_equals, key: behavior, value: retreat }, { kind: flee_nearest,  where: { key: human, value: true } } ] }

Source: apps/wage-engine/src/games/bots_vs_humans/game.json.

Asymmetric games

Pin humans to their team so joiners never land on the bot team:

teamAssignment: { humanTeamId: blue, botTeamId: red }