Overview

Photosynthesis is a strategy game where players grow trees in a forest, collecting light points from the sun as it rotates around the board. Trees cast shadows on smaller trees, blocking their light. Players spend light points to plant seeds, grow trees, and collect scoring tokens by completing a tree’s life cycle. The game lasts 3 full sun revolutions (18 rounds).

Components

• 1 game board (hexagonal forest grid with soil fertility zones)
• 1 Sun Segment
• 4 Sun Revolution Counters (1st, 2nd, 3rd, and 4th for advanced play)
• 4 Player Boards
• 1 First Player Token
• 24 Scoring Tokens (in 4 stacks by soil fertility)
• 4 Light Point Trackers
• 24 Seed Tokens (6 per player)
• 32 Small Trees (8 per player)
• 16 Medium Trees (4 per player)
• 8 Large Trees (2 per player)

Setup

1. Place the main board centrally; give each player a Player Board, Light Point Tracker, 6 Seeds, and 14 Trees (8 small, 4 medium, 2 large).
2. On each Player Board, place 4 Seeds, 4 Small Trees, 3 Medium Trees, and 2 Large Trees on their spaces. Set Light Point Tracker to 0.
3. Keep remaining pieces (2 Seeds, 4 Small Trees, 1 Medium Tree) in the available area beside the Player Board.
4. Stack Scoring Tokens in 4 piles by leaf count, highest value on top.
5. Youngest player takes the First Player Token.
6. In turn order, each player places 1 Small Tree on an outer edge space (1-leaf zone). Then repeat for a second Small Tree.
7. Place the Sun Segment on the sun symbol. Stack Revolution Counters 1st-3rd on the board edge (add 4th for advanced play).

Turn Structure

Each round has two phases:

1. Photosynthesis Phase

The First Player moves the Sun Segment clockwise to the next position (skipped on the very first round). All players simultaneously count light points earned:

Tree Size	Light Points
Small Tree	1
Medium Tree	2
Large Tree	3
Seed	0

Trees in shadow earn no light points. Maximum 20 light points at any time.

2. Life Cycle Phase

Starting with the First Player and going clockwise, each player spends light points on any number of actions. A player completes all their actions before the next player goes.

Critical rule: Each space on the main board can only be activated once per player per turn.

Actions

Action	Cost	Details
Buy	Varies	Purchase seeds/trees from Player Board to available area (buy from bottom up in any column)
Plant a Seed	1 LP	Place an available seed within range of one of your trees
Grow: Seed to Small	1 LP	Replace seed with small tree from available area
Grow: Small to Medium	2 LP	Replace small tree with medium tree
Grow: Medium to Large	3 LP	Replace medium tree with large tree
Collect	4 LP	Remove a Large Tree; take top Scoring Token matching soil type

Seed planting range:

• From a Small Tree: 1 space
• From a Medium Tree: up to 2 spaces
• From a Large Tree: up to 3 spaces

Seeds can be planted in any direction (including non-linear paths) as long as spaces connect.

Shadow Rules

Shadows are cast in straight lines opposite the sun:

Tree Size	Shadow Length
Small	1 space
Medium	2 spaces
Large	3 spaces

A tree only shadows trees of equal or smaller size. Taller trees are not affected. Shadowed trees still cast their own shadows.

Scoring / Victory Conditions

Scoring Tokens come in 4 stacks corresponding to the 4 soil fertility zones (1-leaf outer ring to 4-leaf center). Higher fertility zones yield more points. If a stack is empty, take from the next lower stack.

Game end: After 3 complete sun revolutions (18 rounds), the game ends when the last Revolution Counter is drawn.

Final scoring:

• Sum all collected Scoring Token values
• Add 1 point per 3 unused light points (0-2 remaining light points score nothing)

Highest score wins. Tiebreaker: most seeds and trees remaining on the main board. If still tied, both players win.

2-player variant: Remove the 3 darkest 4-leaf Scoring Tokens. When collecting from the center 4-leaf space, take from the 3-leaf stack instead.

Special Rules & Edge Cases

• Planting a seed activates both the origin tree’s space and the seed’s destination space for that turn.
• You cannot grow a tree and then use it as a seed origin in the same turn.
• You cannot plant a seed and then grow it in the same turn.
• Replaced trees/seeds return to the Player Board on the topmost available space. If no space is available, the piece is discarded to the box permanently.
• Only trees from the available area (not the Player Board) can be placed on the main board; pieces must be bought first.
• Light points accumulate across rounds but never exceed 20.
• The First Player Token passes clockwise at the end of each round.

Advanced Variant Options:

1. Add the 4th Sun Revolution Counter for a longer game (24 rounds).
2. Players cannot plant seeds or grow trees on shadowed spaces.

Player Reference

Phase	Description
1. Photosynthesis	Move sun; all players collect light points for unshadowed trees
2. Life Cycle	Spend light points on actions (buy, plant, grow, collect)

Soil Zone	Leaves	Token Values (descending)
Outer ring	1 leaf	Lowest
Second ring	2 leaves	Low-Medium
Third ring	3 leaves	Medium-High
Center	4 leaves	Highest