The primary action of the game is called Erupting. The nests become mountaintops which explode, spewing molten rock in a specific direction. All eruptions begin when a Cap is moved onto another stack.

The pieces that were under the cap then ‘flow’ out in the same direction, each new piece jumping over and landing farther away away than the piece before it, continuing until the pieces run out or there’s nowhere for the next piece to land, either because it would go off the edge of the board, or because there’s a Cap in the way (since nothing can EVER be placed on top of a Cap).