How to Play Stack Tic Tac Toe (Gobblet Gobblers-style Rules)

Stack Tic Tac Toe is tic-tac-toe where bigger pieces can cover smaller ones. The rules follow the official rules of the board game Gobblet Gobblers. The diagrams below teach you the whole game in about three minutes.

Goal: three of your color in a row

Line up three pieces of your color horizontally, vertically or diagonally to win. Only the top piece you can see on each square counts.

Orange wins with three across the top row

Pieces: two each of small, medium and large

Orange and light blue each start with six pieces: two each of sizes 1, 2 and 3. The number of white dots on a piece’s rim is its size. Pieces not yet on the board are your hand.

On your turn: place or move

On your turn, do exactly one of these:

Place a piece from your hand on an empty square, or on a square you can cover
Move one of your pieces on the board (a top piece you can see) to another square

Place from your hand

Move your piece on the board

Covering: bigger pieces stack on smaller ones

You can cover any smaller piece, whether it is your opponent’s or your own. Pieces of the same or a larger size cannot be covered. A covered piece is hidden and reappears when the piece on top moves away. On the board, a grey rim marks a piece with something buried beneath it, but never shows what is buried.

A small light blue piece

Covered by a large orange piece (something is buried)

Watch what you reveal

Moving a piece reveals whatever was buried under it. If your move leaves your opponent with three in a row, you lose. But if you put the lifted piece back on another square of that same line, the line is broken again and you do not lose.

Moving the large orange piece reveals light blue’s row: orange loses

Covering another square of that row keeps orange safe

Both lines at once: the mover loses

If a single move completes your line and your opponent’s line at the same time, the player who moved loses. Do not reveal your opponent’s line while making your own.

Orange moved and both rows are complete: orange loses

A full board does not end the game

Even when all nine squares are occupied, pieces can still move, so the game goes on. Unlike regular tic-tac-toe, there is no draw on a full board.

Draw: the same position three times

If the same position — the board including buried pieces, both hands, and whose turn it is — occurs three times, the game is a draw. The official rules have no draw, so this rule is specific to this app.

Ways to play

Play against the CPU (Easy, Medium or Hard) or with a friend taking turns on one device. CPU games also offer hints and undo. There is no online play.