Quadrim is played on an board of alternating small and large squares; each small square is surrounded by four large ones and each large square is surrounded by four of each. (It is therefore equivalent to a board of octagons and squares.)
Each player has two types of pieces: blocks (large discs) and pawns (small pointed cylinders). A large square can hold one block or up to four pawns (possibly from both players); a small square can only only a pawn.
On a turn both players roll two dice and the high roller gets to move; they can move two pieces, one with each die, or one piece using the sum of the dice. If they exceed the opponent's roll by at least four they must move blocks, otherwise they must move pawns.
The object of the game is to either surround the center square with your pieces or capture all opposing pieces. Capturing is generally done by occupying the large squares adjacent to opposing pieces with your own (there are seven different cases covered in the rules).
The game board is made of rolled-up vinyl, packaged with the pieces and rules in a large tube.