Planet Unknown

The base game supports one to six players. Begin with symmetric planets and Universal Coalition if learning, and prepare civilization cards and objectives for the player count.

In multiplayer, the commander rotates the station or leaves it still. Everyone simultaneously chooses a top tile from the two stacks in their assigned depot.

The first tile touches the planet perimeter; later tiles connect orthogonally to existing tiles. Align with the grid without overlap or overhang, subject to technologies and special board rules.

After placement, advance for both resources shown, regardless of tile size. Choose which resource to resolve first.

A water resource advances water only if at least one of its water-terrain squares covers planetary ice. Other placement may be legal without earning that advancement.

Energy has no track. Advance the tile's other resource, or a resource corresponding to terrain orthogonally adjacent to the energy terrain area established by the placement.

Place a meteorite on a placed tile's meteor symbol. Rovers spend movement along orthogonal grid squares and collect lifepods or meteorites they pass over. Covering a rover or lifepod with a tile destroys it.

Milestones provide civilization cards, technology, rovers, or biomass. A biomass patch has terrain but no resource, so placing it does not advance biomass again.

Finish the round when a player cannot place either available tile, or both stacks of any depot run out. A player unable to place still chooses a tile and gains its two resource advancements without placing it. When using Events, the final Event card also triggers the last round.

Score complete meteorite-free rows and columns, the highest reached track medals, recovered objects, civilization cards, and objectives. Highest multiplayer score wins. Solo uses clockwise one-depot rotation, Events, private objectives, and an Event-adjusted target score.