# Adding a talkable NPC

An NPC/sign is just an immovable `Entity` that mixes in `Dialogable`. Bumping it
(a rejected move) opens the dialogue box. Talking is the same everywhere — you
only supply **art** + **a story**.

## 1. Write the story

Create `stories/<name>.ink` — a line, a few choices, an ending:

```ink
yo wassup

* kick the sign
    it doesnt budge.
* [say nothing] you have nothing to say to a sign.
- -> END
```

## 2. Compile it

The game can't parse `.ink` (LÖVE has no lpeg), so compile to a `.lua` book:

```sh
lua tools/compile_ink.lua <name>
```

Re-run this **every time you edit the `.ink`** — the game loads the `.lua`, not
the `.ink`. (Needs `lua` + `lua-lpeg` installed.)

## 3. Load the book

In `main.lua`, next to `startSignBook`:

```lua
<name>Book = require "stories.<name>"
```

## 4. Make the entity

In `npc.lua`, copy `Sign` — pick your art and name your book:

```lua
Oracle = class("Oracle", Entity)
Oracle:include(Dialogable)

function Oracle:initialize(x, y)
	self.book = oracleBook            -- from step 3
	Entity.initialize(self, {
		x = x, y = y, color = "red",
		collision = "unmoveable",
		sprites = {
			red   = loadSprite("art/npc/oracle_r.png"),
			green = loadSprite("art/npc/oracle_g.png"),
			blue  = loadSprite("art/npc/oracle_b.png"),
		},
	})
end
```

Per-channel art lives in `art/npc/` as `<name>_r/_g/_b.png` (16px cells).

## 5. Place it in a room

Map a save class to your entity in `Room:createEntity` (`room.lua`), alongside
the `npc` → `Sign` branch:

```lua
if class == "oracle" then
	local entity = Oracle:new(x, y)
	self:registerNpc(entity)
	return entity
end
```

Then add it to a room's `rooms/<room>.sav` `objects` list:

```lua
{ class = "oracle", x = 4, y = 8 }
```

That's it — walk into it and it talks. NPCs are stamped into every colour's
collision matrix, so they block movement and obey the world's colour rules (a
red-only player reads them in red).