1.14 
Gobblet – Strategy Game
To play Gobblet, run the PLT Games program. (Under Unix, it’s called plt-games).
Gobblet! is a board game from Blue Orange Games:
Our 3x3 version actually corresponds to Gobblet! Jr., while the 4x4 version matches Gobblet!.
The Blue Orange web site provides rules for Gobblet! Jr. and Gobblet!. The rules below are in our own words; see also the Blue Orange version.
1.14.1 Game Rules
The 3x3 game is a generalization of tic-tac-toe:
The object of the game is to get three in a row of your color, vertically, horizontally, or diagonally. Size doesn’t matter for determining a winner.
Each player (red or yellow) starts with 6 pieces: two large, two medium, and two small.
On each turn, a player can either place a new piece on the board, or move a piece already on the board – from anywhere to anywhere, as long as the “from” and “to” are different.
A piece can be placed (or moved to) an empty space, or it can be placed/moved on top of a smaller piece already on the board, “gobbling” the smaller piece. The smaller piece does not have to be an opponent’s piece, and the smaller piece may itself have gobbled another piece previously.
Only visible pieces can be moved, and only visible pieces count toward winning. Gobbled pieces stay on the board, however, and when a piece is moved, any piece that it gobbled stays put and becomes visible.
If moving a piece exposes a winning sequence for the opponent, and if the destination for the move does not cover up one of the other pieces in the sequence, then the opponent wins – even if the move makes a winning sequence for the moving player.
Technically, if a player touches a piece, then the piece must be moved on that turn. In other words, you’re not allowed to peek under a piece to remind yourself whether it gobbled anything. If the piece can’t be moved, the player forfeits. This particular rule is not enforced by our version – in part because our version supports a rewind button, which is also not in the official game.
The 4x4 game has a few changes:
The object of the game is to get four in a row of your color.
Each player (red or yellow) starts with 12 pieces: three large, three medium-large, three medium-small, and three small.
Each player’s pieces are initially arranged into three stacks off the board, and only visible pieces can be moved onto the board. The initial stacks prevent playing a smaller piece before a corresponding larger piece.
When a piece is moved from off-board onto the board, it must be moved to either (1) an empty space, or (2) a space to gobble an opponent’s piece that is part of three in a row (for the opponent). In other words, a new piece can gobble only an opponent’s piece, and only to prevent an immediate win on the opponent’s next turn. These restrictions do not apply when a piece that is already on the board is moved.
1.14.2 Controls
Click and drag pieces in the obvious way to take a turn. The shadow under a piece shows where it will land when you drop it.
Use the arrow keys on your keyboard to rotate the board. Use the - and = keys to zoom in and out. Use _ and + to make the game smaller and larger. (Changing the size adjusts perspective in a slightly different way than zooming.) Depending on how keyboard focus works on your machine, you may have to click the board area to make these controls work.
The button labeled < at the bottom of the window rewinds the game by one turn. The button labeled > re-plays one turn in a rewound game. An alternate move can be made at any point in a rewound game, replacing the old game from that point on.
1.14.3 Auto-Play
Turn on a computer player at any time by checking the Auto-Play Red or Auto-Play Yellow checkbox. If you rewind the game, you can choose an alternate move for yourself or for the auto-player to find out what would have happened. The auto-player is not always deterministic, so replying the same move might lead to a different result. You can disable an auto-player at any point by unchecking the corresponding Auto-Play"checkbox.
Important: In the 3x3 game, you cannot win as yellow against the smart auto-player (if the auto-player is allowed to play red from the start of the game). In other words, red has a forced win in the 3x3 game, and the smart auto-player knows the path to victory. You might have a chance to beat the red player in the default mode, though, which is represented by the Ok choice (instead of Smart) in the Auto-Play Options dialog.
Configure the auto-player by clicking the Auto-Play Options button. Currently, there’s no difference between Smart and Ok in the 4x4 game.