# VASSAL Reference Manual Home > Module > Game Piece Palette > Game Piece > Does not Stack
## Does not Stack
The 'Does Not Stack' trait's primary function is that it prevent a piece from forming stacks with other pieces on the board. The trait also controls how players interact with the piece when trying to manually select or move it. Any selection or movement limitations do not apply when the piece is moved automatically by other commands. Select Piece: This option controls what happens when a player tries to select a piece. Options are: normally The piece can be selected normally. when shift-key down A player must hold the Shift key down to select the piece. when alt-key down A player must hold the Alt key down to select the piece. never The piece can never be selected by a player. Move Piece: This option controls what happens when a player tries to move a selected piece. Options are: normally The piece can be moved normally. only if selected The piece can only by moved if it is selected. never The piece can never be moved manually by a player. Ignore grid when moving? Select this option to prevent the piece from snapping to the nearest grid location when it is moved EXAMPLE: Use non-stacking pieces to represent playing cards in games that mix cards and counters, so that the cards can be placed on a map without interfering with stacks of counters. EXAMPLE: Pieces that represent map features, such as destroyed bridges or control markers, can use the "Move piece never" option so that players do not inadvertently move them around. |