Mouse slip

A mouse slip is a physical input error in digital chess. The player has a particular move in mind, but while clicking, dragging, or releasing a piece selects the wrong piece or destination square. On touchscreens the same kind of mistake is often called a misclick or mistap, although mouse slip remains common chess slang even when no mouse is involved.

The important distinction is intention. If a player miscalculates and deliberately makes a bad move, that is a chess mistake, often called a blunder when it is serious. If the player meant to release the queen on one square but the cursor drops it on a neighboring square, the failure is in execution. In an online game, however, a legal move received by the platform normally stands; takeback and confirmation options depend on the platform and game mode.

Some interfaces provide move confirmation to reduce these accidents. Chess.com, for example, offers Confirm Each Move, requiring an extra confirmation before a move is submitted. That protection adds an action and can be impractical with very little time, especially when losing on the clock is a risk. A premove, by contrast, is deliberately entered in advance and is not a mouse slip.