Disc-Triangles (1994)

Disc-Triangles is one of A-O-A's "Big Games," with a 25" x 25" board (large for an abstract) and pieces 3" across. The game is a sort of Reversi/Othello variant - as in that game, you try to surround the opposing pieces and flip them over to your color. The difference is in how surrounding works. Here, you can do it either Go-style (occupy all points orthogonally adjacent to a group) or with three pieces that form the points of a right triangle (flipping all pieces inside the triangle). In an additional twist, the outer edge of the board can only be played on when forming a triangle, and otherwise can be used to help surround pieces. The game is basically for 2 players, but claims it can be played by 4 in teams.