Thunderbird can be played as a competitive game for two (or four as partners,) as a series of solitaire games or puzzles, or as a means of creating ornamental or figurative designs. The game board consists of an 8x8 grid of squares, with 64 square playing pieces in the following combination: 8 Junctions, 28 Diagonals, and 28 Crosses. Each square has a red and a blue line, in one of three of the aforementioned patterns.
In the competitive game, players choose blue or red, and take turns placing their pieces in an attempt to be the first to connect all four sides of the board with paths of their color. Several methods of drawing pieces are provided in the rules, ranging from complete chance to a perfect knowledge of each other's pieces. Variations are also provided for winning by reaching different objectives or scores.
Solitaire games include shuffling and drawing the pieces at random while trying to complete objectives such as placing all the pieces without mismatching the colored lines.
Included in the instructions are 56 diagrams of the board and pieces featuring only the red lines; assembling these designs reveals the whole picture.