Soluna is a simple and fast-playing 2-player brain teaser for adults or children.

The game consists of twelve double-sided discs; each disc has one of four space-themed symbols (sun, stars, moon, comet) on one side, and a different symbol on the other side. Players alternate to combine discs or stacks (of discs) on the table, until one player has no valid turn.

Goal

The first player to win four rounds wins the game.

A round is won when a player blocks their opponent, by leaving them no valid turn.

Start of Game/Start of Round

All discs are placed randomly on the table, one by one (alternately), by the two players. Each disc's face (side) is also chosen randomly. This results in a varied set of symbol at the start of each round.

Players take their turns, alternately.

• For the first round, players decide amongst themselves who should start.
• For all other rounds, the player who lost the previous round should start.

Turn summary

On their turn, a player takes one stack and places it on another stack that is either:

• same height
• same top symbol (compare only the symbol on the top disc of stacks)

Stacks cannot be divided.

If a player is unable to make a valid move, see "End of the round" below.

End of the round

The round ends when one of the players cannot move any stack: that player has lost the round (and the other player wins that round).

For example, a round will end with either of these two scenarios:

• All 12 discs are together in one stack (the other player cannot put a stack onto another stack)
• Both of these are true:

1. all stacks have different symbols on their top disc, and
2. all remaining stacks have different heights (all contain a different number of discs)