About this game

Domino Physics is the purest spacing puzzle on the site. There is no grid and no snapping: you decide exactly where each piece goes, and the chain either carries or it does not. The arc drawn around the placement marker shows how far a toppling domino can actually reach, which turns guesswork into geometry.

The failure modes are symmetrical and both instructive. Too far apart and a falling piece never touches the next one. Too close together and a piece cannot rotate far enough to build the speed it needs — the chain moves, but it runs out of energy within a few pieces.

How to play

  1. Tap along the floor to place dominoes. Z removes the last one, so experiment freely.
  2. The dashed arc around the marker shows how far a toppling piece reaches.
  3. Steps and raised platforms change the surface height — the chain has to climb them.
  4. Press Enter to tip the leftmost domino.
  5. Ring every bell with that one chain to clear the run.

Physics mechanics

Here is what the simulation is actually doing while you play.

Toppling threshold

A domino falls when its centre of mass passes beyond its base. Because the base is narrow, a very small rotation is enough — which is why a light touch propagates a chain.

Potential to rotational energy

As a piece falls it converts height into rotational speed. A piece that has fallen further arrives faster and transfers more energy, so spacing controls how much energy each link receives.

The spacing window

The workable gap is roughly between a third and two-thirds of a domino's height. Below that, pieces do not gather speed; above it, they miss.

Height changes

A domino toppling up onto a step has less effective reach, and one toppling down from a step has more. Uneven ground is why uniform spacing fails.

Amplification along the chain

Each domino knocks over a piece that stores slightly more potential energy than it released, because the falling piece arrives with speed rather than from rest. In a real domino chain this amplification is dramatic — a chain of progressively larger pieces can grow enormously. Here every piece is the same size, so the amplification is small and friction eventually wins, which is exactly why a very long run needs tighter spacing near its end.

Objective

Ring every bell in the run with a single chain, using the dominoes in your budget.

Scoring

  • Each bell is worth 250 points plus up to 250 more for a fast cascade.
  • Clearing a run awards 400 points plus 60 for each unused domino.
  • Undo is free and does not affect score.

Scores, favourites and play history are stored in your own browser using localStorage. There is no account, no leaderboard and no server: clearing your browser data clears them, and they do not follow you to another device.

Tips

  1. Use about two-thirds of a domino height. That spacing is reliably inside the window on flat ground and leaves room for error.
  2. Tighten before a climb. A chain going up a step loses reach. Place those pieces closer together than the rest.
  3. Loosen after a drop. Coming down from a step, pieces have extra reach and extra speed. You can space them wider and save dominoes.
  4. Test the whole line visually. Before pressing Enter, check that every consecutive pair has its reach arcs overlapping.
  5. Bells need a moving piece. A domino that comes to rest against a bell does not ring it. Make sure the bell is inside the swing, not at the very end of it.

Difficulty

Medium. Flat runs are straightforward once the spacing window clicks. The steps from run three onward are what make it interesting, because uniform spacing stops working and you have to think in terms of reach rather than gaps.

Features

  • Free placement with no grid — spacing is entirely yours
  • Visible reach arc showing how far a toppling piece can fall
  • Steps and raised platforms that break even spacing
  • Bells that must all be rung by one chain
  • Undo, so experimenting costs nothing

How accurate is this?

Physics Arcade games use simplified, tuned physics built for playability. They are not scientific simulations: forces, masses and timings are chosen because they feel good at 60 frames per second, not because they match measured values. Where a game departs from real-world behaviour in a way that matters, the game page says so.

Domino Physics – FAQ

Why did my chain stop halfway?

Almost always spacing. Either a gap was too wide for a falling piece to reach the next, or a run was so tight the pieces could not build speed.

Can I place dominoes on the raised steps?

Yes. The placement marker automatically sits on whatever surface is beneath it, including platforms.

Does undo cost anything?

No. Undoing returns the domino to your budget with no score penalty, so experimenting is free.

Why do some bells not ring even when a domino touches them?

The domino has to be moving. A piece that has already come to rest against a bell will not register.