## Behaviors

Behaviors are **inline configs** placed directly inside object YAML (`gather:`, `talk:`, `use:`,
`safespot:`) or mob YAML (`talk:`, `shop:`, `steal:`). Each section below shows the keys for
each behavior type.

### Gather (mining, fishing, woodcutting)

Gather configs live under the `gather:` key on an object. The object's filename is its ID.

Mining — per-drop depletion on a rock:

```yaml
name: copper rock
color: "B2"
gather:
    skill: mining
    tools:
        - pickaxe
    success:
        base: 0.40
        per_level: 0.01
        cap: 0.95
    gather_message: "You swing your pickaxe at the rock..."
    fail_message: "You chip away but get nothing useful."
    drops:
        - item_id: copper_ore
          level: 1
          xp: 17
          weight: 90
          depletes: true
          success_message: "You manage to mine some {B2}copper ore{/}."
        - table: gem_table
          weight: 10
          depletes: false
          success_message: "You spot a glint of something valuable!"
    respawn_timer: 50
    respawn_broadcast: "A glint of copper catches your eye from some {name}."
```

Fishing — non-depleting:

```yaml
name: fishing spot
gather:
    skill: fishing
    tools:
        - fishing_rod
    bait: fishing_bait
    success:
        base: 0.30
        per_level: 0.01
        cap: 0.90
    gather_message: "You cast your line into the water..."
    fail_message: "Nothing seems to bite."
    drops:
        - item_id: raw_trout
          level: 5
          xp: 20
          weight: 100
          depletes: false
          success_message: "You catch a {45}raw trout{/}!"
```

Woodcutting — shared depletion with bird's nests:

```yaml
name: oak tree
color: "71"
gather:
    skill: woodcutting
    tools:
        - axe
    success:
        base: 0.40
        per_level: 0.01
        cap: 0.90
    gather_message: "You swing your axe at the oak tree..."
    fail_message: "You swing but get no logs."
    drops:
        - item_id: oak_logs
          level: 15
          xp: 37
          weight: 100
          depletes: false
          success_message: "You get some {71}oak logs{/}."
    respawn_timer: 14
    deplete_timer: 45
    nest_chance: 256
    respawn_broadcast: "An {name} grows back."
```

Regular tree — always depletes on first gather:

```yaml
name: tree
gather:
    skill: woodcutting
    tools:
        - axe
    success:
        base: 0.50
        per_level: 0.01
        cap: 0.95
    gather_message: "You swing your axe at the tree..."
    fail_message: "You swing but get no logs."
    drops:
        - item_id: logs
          level: 1
          xp: 25
          weight: 100
          depletes: true
          success_message: "You get some {6B}logs{/}."
    respawn_timer: 80
    respawn_broadcast: "A {name} grows back."
```

#### GatherConfig Fields

| Field | Type | Description |
|-------|------|-------------|
| `skill` | string | Skill name for level check |
| `tools` | []string | Required tool_type list (e.g. `[pickaxe]`, `[axe]`) |
| `no_tool_speed` | float64 | Base wait in ticks when no tool is held |
| `bait` | string | Required bait item (for fishing) |
| `success` | SuccessFormula | Base + per_level, capped |
| `gather_message` | string | Message when gathering starts |
| `depleted_message` | string | Message when resource is depleted |
| `exhausted_message` | string | Message when tree falls |
| `fail_message` | string | Message on failed gather |
| `broadcast_message` | string | Broadcast to room on successful gather |
| `drops` | []DropEntry | Weighted drop entries |
| `respawn_timer` | float64 | Ticks until depleted object respawns |
| `respawn_broadcast` | string | Broadcast when object respawns |
| `deplete_timer` | float64 | Ticks for shared depletion (trees) |
| `nest_chance` | int | 1/N chance for bird's nest alongside normal drop |

#### SuccessFormula

| Field | Type | Description |
|-------|------|-------------|
| `base` | float64 | Base success chance (0.0–1.0) |
| `per_level` | float64 | Chance increase per skill level |
| `cap` | float64 | Maximum success chance |

#### DropEntry

| Field | Type | Description |
|-------|------|-------------|
| `item_id` | string | Item ID to drop |
| `table` | string | Reference to a shared drop table in `data/drops/` |
| `weight` | int | Relative drop weight |
| `level` | int | Skill level required for this drop |
| `xp` | int | XP awarded when this drop lands |
| `depletes` | bool | Resource depletes on this drop |
| `quantity` | int | Amount to drop (1–3 for random) |
| `success_message` | string | Player message on drop (supports color tags) |
| `tool` | string | Only drops when this tool_type is active |

Drop messages support inline color tags: `{<00–FF>}text{/}` and gradients `{g:C4,52}text{/}`.
Use the item's color index to match its display color.

#### Shared depletion

When `deplete_timer > 0`, the tree has a shared despawn timer:
- Timer starts at `deplete_timer` max when the first player begins chopping.
- Each tick, if anyone is chopping, the timer counts down.
- When the timer reaches 0, the NEXT successful gather depletes the tree.
- If no one is chopping and the tree isn't depleted, the timer ticks back UP.
- All players chopping the same tree are interrupted when it depletes.

Use `deplete_timer` for trees. Use `depletes: true` on individual drops for rocks.

#### Bird's nests and the `search` command

When `nest_chance > 0`, each successful gather has a 1/N independent chance to also drop a
bird's nest. The nest goes to inventory (or to the ground if inventory is full).

Use the `search` command to open searchable items in your inventory:

```
search <item>          e.g. search nest
                       e.g. search birds nest
```

Searches your inventory for the named item. If found, removes it and rolls on a drop table
(currently `birds_nest_drop`). Only bird's nests are searchable at present.

---

### Talk (dialog trees)

Talk configs go under the `talk:` key on objects or mobs. A conversation is a set of named
**nodes**, each with messages, optional action, and choices for the player.

```yaml
name: Guard
talk:
    nodes:
        start:
            messages:
                - "\"Halt! This area is restricted.\" The guard eyes you suspiciously."
            options:
                - text: "\"What's behind that gate?\""
                  goto: about_gate
                - text: "\"I have copper ore.\""
                  goto: trade_ore
                  condition:
                      has_item: copper_ore
                - text: "\"I have a pass.\""
                  goto: has_pass
                  condition:
                      player_flag: got_pass
                - text: "\"Goodbye.\""

        about_gate:
            messages:
                - "\"Supplies. Weapons. Bring me copper ore and I'll stamp you a pass.\""
            action:
                set_player_flags:
                    talked_to_guard: true
            options:
                - text: "\"I'll be back.\""
                - text: "\"I have some right here.\""
                  goto: trade_ore
                  condition:
                      has_item: copper_ore

        trade_ore:
            messages:
                - "\"Good quality ore.\" He stamps a pass and hands it to you."
            action:
                take_item: copper_ore
                give_item: pass_stub
                set_player_flags:
                    got_pass: true
            options:
                - text: "\"Thanks.\""

        has_pass:
            messages:
                - "\"Alright, I'll open the gate.\""
            action:
                set_global_flags:
                    gate_open: true
            options:
                - text: "\"Thanks.\""
```

#### TalkNode fields

| Field | Type | Description |
|-------|------|-------------|
| `messages` | []string | NPC dialogue, shown one at a time. Player presses enter to advance. Options appear after the last message. |
| `message` | string/list | Single message or randomized list (picks one at random). |
| `condition` | Condition | If condition fails, the node is skipped via `goto`. |
| `action` | NodeAction | Fires when the node is entered. |
| `options` | []TalkOption | Player choices. Empty + `goto` set = auto-advance. |
| `goto` | string | Node ID to auto-advance to when no visible options or condition fails. |

#### TalkOption fields

| Field | Type | Description |
|-------|------|-------------|
| `text` | string | Player-facing choice text |
| `goto` | string | Node ID to navigate to. Omit to end conversation. |
| `condition` | Condition | Only show if condition passes |
| `action` | NodeAction | Fires when selected, BEFORE navigating to `goto` |

#### Multi-message nodes

`messages` is a list of NPC lines shown one at a time with `[enter to continue]` prompts:

```yaml
nodes:
    sign_reminder:
        messages:
            - "\"Yeah, just us two! Not a lot of people heading into the belt these days.\""
            - "\"But we'll be landing shortly! Look at the information sign.\""
        options:
            - text: "\"Okay, thanks.\""
            - text: "\"Goodbye.\""
```

#### Randomized messages

Use a list under `message` to pick one at random each time the node is visited:

```yaml
nodes:
    greeting:
        message:
            - "\"Hello, traveller.\""
            - "\"Ah, you again.\""
            - "\"A visitor! Pull up a chair.\""
            - "\"Back so soon?\""
        options:
            - text: "\"Hello.\""
```

#### Linear auto-advance

When a node has no visible options and `goto` is set, it auto-advances:

```yaml
nodes:
    monologue_1:
        message: "The elder clears his throat..."
        goto: monologue_2
    monologue_2:
        message: "\"Long ago, before the asteroid was settled...\""
        goto: monologue_3
    monologue_3:
        message: "\"...a great darkness fell upon these halls.\""
        goto: choice_point
    choice_point:
        message: "\"Do you understand?\""
        options:
            - text: "\"I think so.\""
            - text: "\"Not really.\""
```

#### Conditional nodes

A node with a `condition` gates the entire node. When the condition fails, the node is skipped
and goes to `goto`. This lets you branch the entire conversation based on player state:

```yaml
nodes:
    start:
        condition:
            player_flag: finished_tutorial
            not: true
        messages:
            - "\"Welcome, newcomer! Need help getting started?\""
        goto: returning_player
        options:
            - text: "\"Yes, where do I go?\""
              goto: directions
    returning_player:
        messages:
            - "\"Ah, you're back! I heard you handled that raid.\""
        options:
            - text: "\"The loot was worth it.\""
```

When `finished_tutorial` is set, `start` fails → jumps to `returning_player`. When unset,
the player sees the newcomer message and options. Node conditions compose with option
conditions: if the node condition passes, each option's condition is checked independently.

#### Option-level actions

Actions on options fire when selected, BEFORE navigating to `goto`:

```yaml
nodes:
    start:
        messages:
            - "Houses are 10 credits. Interested?"
        options:
            - text: "Yes, I'll buy one."
              action:
                  credits: -10
                  set_player_flags:
                      owns_house: true
              goto: purchased
              condition:
                  player_flag: owns_house
                  not: true
            - text: "No thanks."
        purchased:
            messages:
                - "The plot is yours. Use the Estate Directory to enter."
            options:
                - text: "Thanks!"
                  goto: start
```

If an option has both `action` and `goto`, action runs first, then navigation.

#### Node/option action vocabulary

| Field | Effect |
|-------|--------|
| `set_global_flags` | Sets global flags (shared by all players) |
| `set_player_flags` | Sets player-local flags (per-character, saved to YAML) |
| `give_item` | Gives an item to the player's inventory |
| `take_item` | Removes an item from the player's inventory |
| `teleport` | Moves the player to a room ID |
| `heal` | Restores that many hitpoints (clamped to MaxHP) |
| `credits` | Positive = award, negative = charge |
| `aps_node` | Marks this room's APS node as unlocked |

All fields in a single action are processed together:

```yaml
action:
    take_item: dragon_head
    give_item: dragon_slayer_medal
    set_player_flags:
        dragon_quest: complete
        dragon_slain: true
    heal: 99
    teleport: 1
```

---

### Shops

A shop is a **root-level `shop:` property on a mob** (not part of the talk tree). Any mob
with a `shop:` block can be traded with from the game prompt — no separate shop mode:

```
list                 Show shop inventory
buy <item>           Buy an item (partial names work)
buy <N> <item>       Buy a quantity
buy all <item>       Buy as many as you can afford/carry
sell <item>          Sell an item
sell <N> <item>      Sell a quantity
sell all <item>      Sell your entire held stack
```

With multiple shops in a room, disambiguate: `list <mob>`, `buy <item> from <mob>`, `sell
<item> to <mob>`.

#### Pricing

Shops never define per-item prices — prices derive from each item's `value:` field:
- **Buy price** is always **100% of the item's value**.
- **Sell price** uses the OSRS store formula: `value × max(10, buy_percent − stock ×
  change_percent) / 100`. With defaults (buy_percent: 40, change_percent: 3), an item sells
  for 40% of value at zero stock, dropping 3% per unit in stock, floor 10%.

#### Stock and restocking

Each shop item carries a `stock` (target/max and starting amount). Buying depletes stock;
selling raises stock, lowering sell prices. Every `restock_ticks` the current stock moves
one step toward the target. Items with no `restock_ticks` use the global default (1000
ticks). Items a player sold that the shop didn't list are held as dynamic stock that decays
to 0.

#### Shop fields

| Field | Description |
|-------|-------------|
| `shop.message` | Optional greeting shown at top of `list` |
| `shop.buy_percentage` | Sell price at zero stock, % of value (default 40) |
| `shop.change_percentage` | Sell price drop per unit of stock, % of value (default 3) |
| `shop.buys_anything` | Accept items not in its list (default true) |
| `shop.items[].item_id` | Item definition ID |
| `shop.items[].stock` | Target/maximum and starting stock |
| `shop.items[].restock_ticks` | Per-item restock interval (default 1000) |

Example — General Store:

```yaml
name: Shopkeeper
protected: true
shop:
    message: "\"Welcome to the General Store!\""
    items:
        - item_id: fishing_rod
          stock: 10
        - item_id: fishing_bait
          stock: 1000
        - item_id: hammer
          stock: 10
talk:
    nodes:
        start:
            message: "\"Type 'list' to see my wares.\""
            options:
                - text: "\"Goodbye.\""
```

---

### Interaction Reference

The `Interaction` struct is the shared shape used by `on_use`, `on_look`, `on_kill`,
`on_traverse`, on_enter steps, and trigger steps. When a list of interactions is evaluated,
the first whose condition passes wins and fires.

| Field | Type | Description |
|-------|------|-------------|
| `item_id` | string | `on_use`: required item (empty = bare `use <obj>`). `on_look`: only fires if carrying this item. `on_kill`: only fires if wielding this weapon. |
| `condition` | Condition | Optional gate |
| `message` | string | Message shown to the player when this entry fires |
| `action` | StepAction | Optional effects (see below) |

#### StepAction / NodeAction vocabulary

The universal effect vocabulary used by all interaction types, talk node actions, on_enter
steps, and trigger steps:

| Field | Type | Description |
|-------|------|-------------|
| `set_global_flags` | map[string]any | Set global flags (cascades other triggers) |
| `set_player_flags` | map[string]any | Set player flags (per-character, saved to YAML) |
| `give_item` | string | Give one unit of an item to inventory |
| `take_item` | string | Remove one unit of an item from inventory |
| `teleport` | int | Move player to a room ID |
| `heal` | int | Restore hitpoints (clamped to MaxHP) |
| `credits` | int | Add (positive) or deduct (negative) credits |
| `aps_node` | bool | Mark current room as discovered APS node |
| `message` | string | Direct message to the player (`%p`/`%v` supported) |
| `broadcast` | string | Announce to all in the room |
| `broadcast_global` | string | Announce to all online |
| `spawn_mob` | string/map | Spawn a transient mob |
| `despawn_mob` | string | Despawn all transient mobs of this id |
| `delay` | int | Ticks to wait (on_enter/triggers only) |
| `condition` | Condition | Per-step gate (on_enter/trigger steps only) |

#### SpawnMobConfig

For transient mob spawning, pass either a bare string (the mob ID) or a map:

```yaml
spawn_mob: rat

# Equivalent to:
spawn_mob:
  id: rat
```

Full config:

| Field | Description |
|-------|-------------|
| `id` | Mob ID to spawn (required) |
| `owner_only` | Private to the triggering player |
| `despawn_on_leave` | Fades when owner leaves allowed rooms |
| `despawn_rooms` | Rooms where the spawn survives |
| `despawn_ticks` | Despawn countdown in ticks |

---

### On Kill — Mob Interactions

Mobs can define `on_kill` — fires when the mob is defeated. Standard loot `drops` hit the
ground first, then the first matching interaction fires. An entry with `item_id` only fires
if the player wields that weapon:

```yaml
name: boss
combat: ...
on_kill:
  - condition:
      global_flag: boss_quest_active
    message: "The boss crumbles to dust!"
    action:
      set_global_flags:
        boss_slain: true
      broadcast_global: "%p has slain the World Boss!"
      spawn_mob: boss_add
  - item_id: dragon_slayer
    action:
      give_item: boss_heart
      set_global_flags:
        dragon_slain: true
```

Task mob `on_kill` works the same way — fires when the work is completed:

```yaml
name: reactor panel
task: ...
on_kill:
  - message: "The panel snaps into place."
    action:
      set_global_flags:
        reactor_repaired: true
      set_player_flags:
        repaired_reactor: true
```