How to Fix a Match-3 Swap Being Allowed When It Creates No Match

In most match-3 designs a swap is only legal if it forms at least one match. If your board lets any adjacent swap through, you are detecting matches after committing rather than before. Validate the swap first.

How to fix it

1. Swap on a copy first

Before committing, swap the two cell values in a scratch copy of the grid (or just compare the two coordinates in place). Run your horizontal and vertical match scan on that hypothetical state.

2. Require a match to commit

Only finalize the swap if the scan returns at least one group of three or more same-colored tiles touching the swapped cells. Track which cells changed so you can scan locally instead of the whole board.

3. Animate invalid swaps back

If no match is found, play a short bounce: move the tiles to the new positions then tween them back. This signals to the player the move was illegal without locking input.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every Unity error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.