Rules

Starting the game

Both players will each decide whether they want to represent Angels (the pieces with yellow halos) or Demons (the red pieces). The board requires no setup, to start the game players only need to indicate their first move.

Moves

Both players will write down either on a piece of paper, white board, or electronic device the row & column of the space they wish to indicate as their move for the turn. Once both players have decided, they will reveal their decisions simultaneously to the other player. The rules for what a move determines are as follows:

• Each player can only select a “black” space to indicate their move.
• A space that is indicated as a move will have the adjacent north, west, east, and south spaces covered with the player's respective pieces.
• If a player indicates a space that does not have all 4 spaces adjacent to it available (i.e. They choose a space in the corner or against the edge of the board), they will only be able to cover spaces that exist within the boundaries of the board. Example: if I chose the bottom left corner from my perspective, I would only be able to place pieces on the spaces directly above and to the right of my decision.
• If [player 1] indicates a space in which some or all of the adjacent spaces have been covered by [player 2] in a previous turn, those spaces are now covered by [player 1].
• If players choose an overlapping space or the same space in a turn, any overlapping spaces that would normally cover now become empty spaces, regardless of their previous state. Example: if I chose a space, and my opponent chose a space directly above mine, the space in between our two moves would now be an empty space if it were covered, or would otherwise be unchanged.
• Any move which tries to cover spaces that are already covered by that player (and doesn't conflict with any of the above rules) is legal, but already covered spaces by the same player will be unaffected.
• Each turn, both players must indicate a valid move. There is no “passing”.

Game length

Traditionally, the game is played in a total of 20 moves. This can be adjusted for player preference, and for more competitive play a move timer is recommended.

Ending the game

The game ends at the conclusion of the final turn. After the final turn has finished resolving, the number of currently covered spaces for each player is tallied and the player with the most covered spaces wins.