These include different setup of the pieces, material-odds games, bughouse, crazyhouse, and Kriegspiel. In variants 0 through 4, each side has eight pawns, in their usual positions, and only the ranks 1 and 8 differ from normal chess. Here are the meanings of each type of wild game. Material-odds wilds and wild 7 are unrated. The white king starts on d1 or e1 and the black king starts on d8 or e8, and the rooks are in their usual positions.
Bishops are always on opposite colors.
Subject to these constraints the position is random. Black's arrangement is always a mirror image of White's. Castling is not allowed. Black's pieces mirror White's, and castling is not allowed. A random set of pieces is generated.