Taking on the process of learning how to play Photosynthesis is admittedly intimidating and a bit difficult but only because it is a masterfully designed board game that makes you really think. There are not many steps to either the setup or the gameplay but wrapping your head around how light and shade works does take a minute. Once you get through that, this hurdle only adds to the incredible depth of strategy in this lightweight engine builder that you can get done in under an hour. This is your guide to how to play Photosynthesis.

FOR MORE: Photosynthesis Page | Photosynthesis Review | Games Like Photosynthesis | Buy Photosynthesis on Amazon


Several varieties of trees compete to grow and spread their seeds in the sunlight of this small, but fertile, forest. As each tree grows its leaves are touched by the sun’s rays, collecting Light Points and casting shadows on the surrounding smaller trees. When a tree reaches the end of its life cycle, players win points proportional to the richness of the soil the tree was rooted in. Learning how to play Photosynthesis is on the harder side but games are fast so it comes quickly.


Time Needed: approximately 45 – 60 minutes

This is a step by step guide for how to play Photosynthesis the popular medium engine-builder board game. Additional notions and special rules can be found below the list. These will be referenced for your convenience.

1. SETUP | Gameboard and Initial Sun Placement
To kick off how to play Photosynthesis, bring out the all mighty sun and forest board. The four-panel board that folds out is your main game board. Place this in the center of the table. Around the edge, there is a yellow light icon representing the sun. Place the separate sun piece centered on top of this marker.

2. SETUP | Player Boards
Each player needs to take a game board to keep track of their trees and score. There are four of these (since you can have up to four players) and the only difference is your player color. There is blue, green, red and yellow.

3. SETUP | Collect Your Seeds and Trees
Every player starts with trees and seeds. Grab these from the box now. Trees come in 3 different sizes and there are spaces on your board indicating which should go where. 4 seed tokens are placed on your board with the other two, and your other trees, are placed off to the side (“available” area).

4. SETUP | Light Track
In the top left corner of your player board is your light track. Grab a sun marker and place it on the “0” space to start. You will move this up throughout.

5. SETUP | Sort and Put Out Score Tokens
Scoring tokens are the larger circles with translucent green leaves on the back of them. Sort these into four stacks depending on whether it has 1, 2, 3 or 4 leaves on the back of it. Then flip these over and put them in order making sure the highest number printed on the front is on top and the lowest number is on the bottom of the stack. Place these beside the master game board. In a smaller game, you do not use the darker “4 leaves” set.

6. SETUP | Put Out Numbered Sun Cards (Turn Markers)
There is a stack of 1 – 4 sun disc to put next to the scoring circles and game board. Only use the “4” if you are playing the expert variant and make sure these are all in order with highest on top. Every time the sun goes all the way around, you remove one of these. Three times (or 4 for a variant) around and the game is over.

7. SETUP | Choose Starting Player
Whoever is the youngest goes first or choose randomly. They are given the starting player chip.

8. SETUP | Take Turns Placing Initial Small Trees
The starting player puts one of their small trees on any outside ring space on the board. You take turns going clockwise until every player has placed 2x small trees. This is the last setup step in how to play Photosynthesis before getting into gameplay steps.

9. GAMEPLAY | Phase 1 | Photosynthesis | Sun Rays
During this phase, the light shines and any trees that soak it up are going to gain light points for you to spend in the next phase to get trees or grow them bigger. The sun piece shines light in straight lines across the entire board. There are arrows on the sun that show how it shines across a particular line of spaces.

10. GAMEPLAY | Phase 1 | Photosynthesis | Scoring Light Points
If you have a tree in the line that is not blocked by the shade of any other trees, it scores light points. Small trees cast a shadow of one space, mediums two and larges three (even if they are your own). If a tree scores it is based on size, small gets one light point, medium two and large three. Take your total points scored and any leftover from previous rounds and mark that total on your light track. You can not have more than 20 at one time and any extra past that are discarded.

11. GAMEPLAY | Phase 2 | Lifecycle Phase
Players take turns during this phase taking their “turn” and then passing to the next player to do the same. Whoever holds the first player token goes first. Here each player can take actions and they can take as many as they want and can afford. You can buy new trees or seeds, grow existing trees or ultimately collect victory point discs. See Actions Explained below for more.

12. GAMEPLAY | Move the Sun Disc One Spot Clockwise
After each player takes their lifecycle phase, the turn ends. To start off a new turn the sun moves one spot clockwise. There are 6 spots around the board where the sun piece settles. When the sun goes all the way around, you remove one of the 3 sun disc tokens and then you loop again. You go around 3 times and then end the game. So with 6 spots and 3 loops, that means each game is going to last 18 turns (6 x 3 = 18).

13. GAME END | Repeat Turns Until Sun Loops 3 Times Around
Continue the phases of the turn as outlined, moving the sun each time, until the sun has moved all the way around the board three times, a total of eighteen movements total. The game immediately ends and you move to scoring. This is the meat of how to play photosynthesis, it may take a second to get the hang of it, but once you do it is easy and quick. As you can see, learning how to play Photosynthesis is not that bad.

14. SCORING | Point Discs + Remaining Light Spot
Scoring is very easy and is made up of two components. First, add together all the numbers on the score discs you earned in the game. Second, take the green total that is to the right of the row your light disc is in. Add that to your score.

15. WINNING | Highest Total Wins
Whoever has the highest overall point total wins. If there is a tie, the tied player with the most trees and seeds combined total wins. See learning how to play Photosynthesis is easy.



You have four columns of things on your board – four seeds, four small trees, three medium trees and two large trees. You can always buy the bottom-most item in each of those columns for the cost shown next to it. The bottom-most thing is important because as you buy things, they get more expensive. This is only to buy and move to your “available area”, nothing you do with buying puts anything on the main gameboard.

To plant a seed you need to pay one light point and that will allow you to take a seed from your “available area” and place it on the game board near one of your existing trees depending on size. It can be placed within one space of a small tree, two spaces of a medium tree and three spaces for a large. Once you plant, you can also not grow that seed in the same turn. You can only do one thing to any one space in any given lifecycle phase.

Pick something you already have and make it bigger. If you look on your chart you will see that a seed grows to a small for one light point, a small to a medium for two points and a large for three. That is the cost to change. You can only grow one tree one step in any given turn. You could not, for example, take a seed to a small and then a small to a medium in the same Lifecycle phase. In order to actually grow something, you do need to have the thing you are growing to ready to go in your “available area” otherwise you cannot do it. When you replace the tree, the tree you removed from the board goes back into the “to buy” section of your board, pushing anything else in the column down to a cheaper price.

Once your trees have matured, you are finally ready to collect your dividends. You can pay four light points to turn a large tree into a point disc. Depending on the space there is going to be a number of translucent leaves, the middle has four while the outside ring has one on each space. Take the top disc of the victory point discs with the same number of leaves as the space that particular tree was on.


If the are no discs left in the scoring disc you are trying to collect from, then you have to settle for the next highest available stack.

Growing has to happen one step at a time. You cannot pay 5 light points to jump from a small tree to a big one.


(1) Include the 4th Sun Revolution Counter, giving the sun another revolution around the board.

(2) Players cannot plant a seed or grow a tree when that seed or tree is shadowed by another tree.


  • Illustrated Rules
  • 1 Game Board
  • 1 Sun Segment
  • 4 Sun Revolution Counters
  • 4 Player Boards
  • 1 First Player Token
  • 24 Scoring Tokens
  • 4 Light Point Trackers
  • 24 Seed Tokens (6 of each color)
  • 32 Small Trees (8 of each color)
  • 16 Medium Trees (4 of each color)
  • 8 Large Trees (2 of each color)


We hope you can now say you know how to play Photosynthesis. This unique engine-builder has really created something new and special unlike we have ever before. It is a great medium that you can fit in under an hour so it is more manageable than most. The strategy becomes about playing on this grid and boxing your opponents out while growing in all the right places, a nervewracking process because there are so many decisions you can make and paths to victory.