Domino Chain — 2D Rigid-Body Toppling Physics (2D)

Build the Chain

Tile height 55 px

Drag spacing 40 px

✏️ Click / drag to place

Chain Status

Place tiles, then press Launch!

Tiles placed

Tiles fallen

How the physics works

Every tile is a rigid rectangle standing on a base edge. It is not a scripted lean-then-fall animation: whether a tile tips at all, and how fast, comes out of integrating a real torque balance about its base pivot every frame.

tipping threshold (geometry, not a timer):
  phi0 = atan( (w/2) / (h/2) )         <- half-width vs half-height

once past phi0, angular acceleration:
  alpha = 3 g r sin(theta - phi0) / (w^2 + h^2)
  r = sqrt((w/2)^2 + (h/2)^2)

Below phi0 that same formula pulls the tile back upright — a push too weak to cross the threshold makes the tile rock forward and settle back, exactly like a real domino that only got grazed. A neighbour hit transfers angular velocity scaled by tile height and a restitution factor; too much spacing, or too big a height jump on the hill you drew, and the incoming corner can miss the next tile entirely — the chain physically breaks, it isn't told to stop.

Click — place one tile at that point.
Drag — lays a path of tiles following your cursor, spaced by the slider — draw hills, valleys or zig-zags; direction of fall between two tiles follows the path itself.
Tile height — taller tiles carry more angular momentum into the next hit but also need a bigger horizontal reach.
Launch! — gives the first tile a real angular kick and starts integrating the chain.

Click or drag on the ground to place tiles

Standing Falling Fallen