Photosynthesis

To set up, place the game board in the center of the play area and position the sun piece on the sun dot. Each player collects a player board, along with matching trees (2 large, 3 medium, 4 small) and 4 seed tokens, placing them on their board in designated areas. Leftover pieces form an available area. Each player places a light token on the '0' space of their light track. Scoring tokens are separated into four stacks based on their leaf backs (1, 2, 3, or 4 leaves), then flipped to show numbers and ordered highest to lowest. These are placed beside the board. In a 2-player game, the darkest colored scoring tokens (4-leaf) are removed. The youngest player takes the first player token. Players then take turns placing two small trees from their available area onto any empty outside edge space of the board.

In Photosynthesis, players strategically place and grow their trees to soak up sunlight and spread their seedlings. The goal is to collect the most light points and convert them into victory points by completing the life cycle of their trees. The player with the highest score after the sun has completed three full rotations around the board will be the winner.

The game is played over a series of rounds, each broken into two phases: Photosynthesis and Life-Cycle. In the Photosynthesis phase, the first player moves the sun board one step clockwise (skipping this in the first round). Players then collect light points based on whether their trees are in the shadow of other trees. Trees cast shadows a certain number of spaces away depending on their height (small: 1, medium: 2, tall: 3). A tree in the shadow of another tree (even its own) does not score light points unless it is taller than the tree casting the shadow. Unblocked small trees gain 1 point, medium trees gain 2 points, and tall trees gain 3 points. Players record their light points on their light track, never exceeding 20. In the Life-Cycle phase, starting with the first player and going clockwise, each player performs as many actions as they want and can afford, in any order, as often as they like. Actions include buying trees or seeds from their player board, planting a seed from an existing tree on the main board, growing a tree on the main board by replacing it with a larger one, or collecting a tall tree from the main board for victory points. A space on the board cannot be targeted more than once per turn for planting or growing actions.

Players gain light points during the Photosynthesis phase based on the height of their unshaded trees on the main board. Small trees yield 1 light point, medium trees 2, and tall trees 3. During the Life-Cycle phase, players can collect tall trees from the main board. When a tall tree is collected, it is returned to the player's board, and the player gains the top-most scoring token from the stack matching the number of leaves on the space the tree was collected from. If that stack is empty, they take from the next lowest stack. At the end of the game, players total the points on their collected scoring tokens and gain additional points based on the final position of their light token on their player board. The player with the most points wins.

The game ends immediately after the Photosynthesis phase of the round in which the sun completes its third full revolution around the board (or fourth if playing with the advanced variation). This is indicated by removing the final sun revolution token from the stack. Players then total their points from collected scoring tokens and any bonus points from their light track. The player with the most points wins. In case of a tie, the tied player with the most seeds and trees on the main board wins. If there's still a tie, tied players share the victory.