Every player builds their own block of stones in Monolyth, using 3D polyominoes to create patches of particular colors, complete levels, and a structure that matches a pattern.

To set up, choose a structure card at random, then place it on the main board, along with the appropriate structure tokens, level tokens, and prophecy tokens based on the number of players. Place the crystal marker next to the main board, then draw twelve random polyominoes from the box and place them in a circle around the main board. The polyominoes come in five colors, and all 1x1 blocks in those colors are placed to the side.