How to Play Photosynthesis | Rules & Setup Guide

Get Ready

Setup the game with these step-by-step instructions before diving into your turn.

Prepare standard components

Set up your own components, main board, scoring tokens, sun segment, and revolution counters as in a normal game

Orient the board

Rotate the board and place the Directional Selection card under the edge furthest from you

Determine first player

Randomly select one player to be the first player

Place photon counter cards

For each Cynthia, place the two Photon Counter cards (0-14 and 15-20) on the table and put Cynthia's photon marker on the "0" space

Give Cynthia her pieces

Provide each Cynthia with 3 seeds, 3 small trees, 3 medium trees, and 2 large trees

Return unused pieces

Return remaining seeds and trees to the box as they will not be used

Place action sequence card

Put the Action Sequence card on the table

Prepare action deck

Arrange action cards face down with Revolution 1 and 2 icons in the upper half, shuffle them, and place on the table

Place Cynthia's starting trees

The first starting tree is a small tree, the second is a medium tree placed according to special rules

Determine valid starting spaces

Valid starting spaces are all empty spaces on the outer ring not adjacent to any tree

Draw for placement

Draw an action card and use the white Directional Selection symbol at the bottom center to determine placement along the outer ring

Place tree on target space

Put Cynthia's tree on the determined target space

Four player setup exception

When no other valid space exists, Cynthia may place trees adjacent to other trees

On Your Turn

What you can do during your turn.

Photosynthesis phase

Cynthia receives photon points like a normal player

Reshuffle at revolution 3

At the start of the third sun revolution, shuffle all action cards and rotate the deck to show the Revolution 3 symbol, then place face down

Draw action card

On Cynthia's turn, draw 1 action card from the deck and place it to the right of the Action Sequence card

Use top half only

Only use the top half of the card showing different parameters for each action

Reshuffle when empty

If the action deck is empty, shuffle all action cards and form a new deck

Check actions sequentially

Start with action 1 on the Action Sequence card and check if Cynthia can perform it; if not, check the next action

Perform maximum one action

Cynthia can only perform a maximum of 1 action per card

Continue drawing cards

Keep drawing cards and performing 1 action per card until Cynthia has no photons, has activated all her spaces, or couldn't perform any action on a card

Action 1 - Collect

Costs 4 photons; Cynthia completes the life cycle of a large tree if her photon score plus the number shown on the action card is greater than or equal to the current sun revolution number

Revolution 3 collecting

During revolution 3, Cynthia also collects a large tree if she has two large trees on the board, prioritizing based on future light check

Collect tiebreakers

Use closest to center, then most future light, then Directional Selection

Action 2 - Grow Tree

Costs vary: 2 photons to small, 4 to medium, 6 to large tree

Check tree sizes

Look at the tree symbol on the action card showing three sizes; start with the smallest checked size and verify if Cynthia can grow such a tree

Grow tiebreakers

Use closest to center, then most future light for Cynthia, then least future light for opponents, then Directional Selection

Action 3 - Plant Seed

Costs 1 photon; count spaces where Cynthia has trees or seeds

Seed planting condition

If this count is less than the current sun revolution plus the number on the action card, Cynthia plants a seed

Revolution 3 seeding

During revolution 3, the count is always 3 regardless of the revolution counter

Ring preference for seeds

The ring symbol indicates which ring Cynthia prefers; read left to right to find the first ring with valid planting space

Seed tiebreakers

Use space with most empty adjacent spaces, then Directional Selection

Determine source tree

When planting a seed, determine the source tree whose space becomes activated

Source tree tiebreakers

Use smallest tree, then tree on outermost ring, then Directional Selection

Future Light Check procedure

Imagine the board change, imagine the sun moving to the next segment, and count photon points the relevant player(s) would collect

Space activation rule

Cynthia follows the "maximum 1 activation per space per turn" rule; track which spaces have been activated

Winning

How to claim victory.

End game tree collection

After the final turn, if Cynthia has a large tree on the board, she completes the life cycle of the tree closest to the center and collects one scoring token without spending any photons

Multiple Cynthia collection

If two Cynthias collect scoring tokens, they do so in player order

Calculate final score

Count the values of Cynthia's collected scoring tokens

No photon points scored

Cynthia does not score points for remaining photon points

Easier difficulty options

Skip end-game tree collection, increase Cynthia's growth costs by 1 photon, or start Cynthia with 2 small trees instead of 1 small and 1 medium

Harder difficulty options

Decrease Cynthia's growth costs by 1 photon, or score remaining trees (small: 1 point, medium: 2 points, large: 3 points)

Advanced variant

When playing the fourth sun revolution variant, reshuffle and rotate action cards at the start of revolution 4 instead of revolution 3