Helpmate

In a helpmate, both sides cooperate to reach a checkmate of the black king. By the usual convention, Black moves first and White makes the mating move. There is none of the resistance found in a directmate: every move is chosen to build the final mating position together.

The notation h#n means a helpmate in n moves. In h#2, the normal sequence is Black, White, Black, then White mate. Some compositions specify multiple solutions, twin positions, meaning slightly modified versions of the diagram, or other conditions; when announced, those possibilities are part of the task rather than defects.

Set play has a special convention in helpmates: there may be an additional solving line that starts with the side that would normally move second, usually White. This is a feature of the composition, not a new rule for ordinary chess games.