Game Loop

Your Lua script is loaded once, then the engine calls three special global functions every frame. If any of them is missing, the engine simply skips it.

Lifecycle overview

Script loaded
     |
     v
 _init()          <-- runs once
     |
     v
+----------+
| _update() | <-- runs every frame (game logic)
|           |
| _draw()   | <-- runs every frame (rendering)
+----------+
     |
     v
   (loop)

_init()

function _init()
  -- create variables, player state, enemy tables, level data...
end

Use _init() to set up your initial game state:

• Initialize player position and stats

• Build tables for enemies, platforms, bullets, pickups

• Set camera state

• Prepare anything that should exist before the first frame

_update()

function _update()
  -- handle input, physics, collisions, timers...
end

Use _update() for all game logic:

• Reading keyboard input

• Moving characters

• Applying gravity

• Updating animation timers

• Checking collisions

• Changing score, health, or game states

_draw()

function _draw()
  clear(0)
  -- draw map, sprites, shapes, UI...
end

Use _draw() only for rendering:

• Clear the screen

• Move the camera if needed

• Draw the tilemap

• Draw sprites and shapes

• Print debug values to the output panel

The golden rule

Important

Update in _update() , draw in _draw() .

Keeping game logic and rendering separate makes your code easier to understand, debug, and extend. Never modify game state inside _draw(), and avoid drawing inside _update().