Multiplicity

Multiplicity is a pure placement abstract strategy game.

The game starts on an empty hexhex board. White moves first, after which turns alternate. Moving is compulsory.

1. The restricted placement phase

White starts by placing one stone on the empty board. From that point on players take turns to:

Place a stone on a cell adjacent to the last stone placed by the opponent, and ... ... place a stone on a cell that has only vacant cells as neighbors.

When the player to move cannot make the second placement of their turn, their turn ends, the restricted placement phase ends, and the free placement phase begins.

2. The free placement phase

Now players take turns placing one stone on any vacant cell.

The game ends when the board has only 1 empty cell remaining. (Now each player has placed the same number of stones.)

The player with the highest score wins. A player's score is the product of the sizes of all his groups. Ties are rare but possible.

Several games by Christian Freeling use this "one bound, one free" placement protocol, which he began exploring in 2012.