Capture & carry

The carry loop — grab, run, score, or get tagged and drop — built from items and interactions. Worked from Capture the Flag and Pirate’s Booty.

1. Declare the item and spawn it

itemTypes:
  - kind: red_flag
    label: "Red flag"
    icon: { type: glyph, value: "⚑", color: "#ef4444" }
items:
  - { kind: red_flag, count: 1, spawnPointId: red_flag }

2. Pick it up (walk-over)

A worldItem + auto interaction is a walk-over grab. Restrict who can take it with initiatorFilters:

interactions:
  - verb: grab_red_flag
    label: "Grab flag"
    target: worldItem
    trigger: auto
    rangeMeters: 5
    itemKinds: [red_flag]
    initiatorFilters: [{ key: teamId, value: blue }]   # only blue can take the red flag

- id: pickup_red_flag
  when: { kind: interaction, verb: grab_red_flag }       # same = grabber, other = the item
  do:
    - { kind: set_state, target: same, key: hasFlag, value: red }
    - { kind: destroy_item }                              # consume the world item
    - { kind: send_event, to: same, event: { type: toast, text: "Grabbed it — run home!" } }

Track carriage in player state (hasFlag) so other rules can check it; the world item itself is consumed and re-spawned later.

3. Score by delivering

- id: blue_score
  when:
    kind: and
    children:
      - { kind: entered_zone, who: any, zoneId: blue_base }
      - { kind: compare, op: eq, left: { ref: same.teamId }, right: blue }
      - { kind: state_equals, who: same, key: hasFlag, value: red }
  do:
    - { kind: set_state, target: same, key: hasFlag, value: null }
    - { kind: increment_state, target: { byTeam: blue }, key: score, by: 1 }
    - { kind: spawn_item, item: red_flag, atPoint: red_flag }   # reset for next round

4. Drop on tag

A proximity rule where same is the carrier and other is an enemy drops the item where it fell so it’s contestable:

- id: blue_carrier_tagged
  when:
    kind: and
    children:
      - { kind: proximity, a: any, b: any, meters: 5 }
      - { kind: compare, op: eq, left: { ref: same.teamId },  right: blue }
      - { kind: state_equals, who: same, key: hasFlag, value: red }
      - { kind: compare, op: eq, left: { ref: other.teamId }, right: red }
  do:
    - { kind: set_state, target: same, key: hasFlag, value: null }
    - { kind: spawn_item, item: red_flag, at: same }    # drop at the carrier's position

All four snippets: apps/wage-engine/src/games/capture_the_flag/game.yaml.

Variations

Marker glow while carrying. Add a theme.playerMarkers rule keyed on the carry state so carriers stand out:
```
theme:
  playerMarkers:
    - { when: { key: carrying, value: true }, color: "#fbbf24" }
```
(Pirate’s Booty does this with carrying.)
One-at-a-time. Add initiatorFilters: [{ key: state.carrying, value: false }] to the grab so a loaded player can’t grab a second.
Consumable currency. For coins kept in inventory rather than a carry flag, remember the picked-up item’s id (set_state … value: { ref: other.id }) so you can destroy_item exactly that one on deposit (Pirate’s Booty’s coin loop).