Circle of Life
Circle of Life Rulebook
Table of Contents
Table of Contents
Game Info
2 players | 20-30 minutes
Equipment: a Circle of Life board, plus one set of differently colored stones per player.
The Circle of Life board is a hexagonal grid of cells for play, surrounded by a ring diagram called the Circle of Life. The ring diagram shows twelve shapes made of hexagons, joined in a circle by arrows. Each arrow points from a shape to the shape it eats.
Definitions
- Critter: any connected group of same-color stones on the board is a critter. A single stone is also a critter.
- Circle of Life: surrounding the board is the Circle of Life, which shows how critters of different species feed. Each species is defined by its shape and can eat one other species, as indicated by arrows — if an arrow points from species A to species B, then A can eat B. All possible species of up to four stones are represented on the Circle of Life.
The twelve species, named by shape, are ordered around the Circle of Life as follows (each name is followed by the species it eats):
- singleton (1 stone) eats 4-line
- 4-line (4 stones) eats propeller
- propeller (4 stones) eats diamond
- diamond (4 stones) eats snake
- snake (4 stones) eats arch
- arch (4 stones) eats sled
- sled (4 stones) eats key
- key (4 stones) eats triangle
- triangle (3 stones) eats 3-line
- 3-line (3 stones) eats 3-bend
- 3-bend (3 stones) eats pair
- pair (2 stones) eats singleton
That closes the circle: pair eats singleton, and singleton eats 4-line again. The exact outline of each named shape is shown on the board itself.
Gameplay
The board begins empty. Players take turns. Each turn has two steps, taken in order:
- Evolve: you must place one stone of your color on any empty space, with one restriction: you may not make a critter containing more than four stones.
- Feed: the critter you evolved in step 1 must eat all enemy critters which are adjacent to it and on which it can feed, per the Circle of Life. Remove eaten critters from the board.
A player wins when she either can't evolve on her turn (meaning she's filled up the ecosystem as much as possible), or has eaten at least 20 stones.
Remarks
- You may devour several instances of the same species at once, if the opportunity occurs.
- A species may arise near one of its predators without risk. Predation only occurs when a token is placed.
- You cannot create a species with a group of more than four stones. Consequently, managing to own territory will limit your possible moves.
Turn Example
In an example turn, the active player first places a stone to evolve a three-stone critter. Then, in the feed step, that newly evolved critter eats an adjacent enemy critter that it preys upon per the Circle of Life, and that enemy critter is removed from the board.
The Game Recreates Key Aspects of Real Ecosystems, With Minimal Rules
- It starts with simple species, which evolve to become more diverse and complex.
- Species get more complex as you go up the food chain.
- Simple species reproduce, die, and evolve at higher rates than more complex ones.
- When a species' population is high, another species often evolves to eat it.
- As in real ecosystems, intransitive competition enables biodiversity.
- When a critter at the top of the food chain dies, it feeds back into the bottom, to complete the Circle of Life.
Beginner Strategy Tips
- Don't eat opponent critters when unnecessary. It's almost always better to delay eating to the last moment. When you eat your opponent's critter, you also give your opponent more flexibility.
- If a critter of yours is sure to be eaten, try to exploit the situation by eating the critter that threatens to eat yours, or set yourself up to eat it after it eats yours.
- Size-4 critters can't evolve, which means if they can be eaten, they will be. Be aware of all the possible ways your opponent can eat a size-4 critter you might make and (usually) don't make it if they can eat it.
- Be aware of the balance between stones played and stones captured as you grow each critter. For example, let's say you have a 2-stone critter that eats an enemy's 1-stone critter, then grows into a 3-stone critter that eats 3 of the opponent's 2-stone critters. That's 3 friendly stones added to the board, for 7 enemy stones removed. Even if your opponent eats your size-3 critter, you'll be ahead after the exchange.
- Try to minimize the number of moves you have left to play and maximize your opponent's. In the late stage, if there is no tactical advantage to be gained, fill the cells that only you can fill before the ones that both you and your opponent can fill.
Design Story
Designer Nick Bentley helped design or develop most of North Star Games' Evolution games, all of which are ecosystem simulations. While doing so, he posed himself the following challenge: make the simplest possible ecosystem game that exhibits key properties of real ecosystems. Circle of Life is the result.
The idea is to represent species with shapes, with rules about which can eat which. The Circle of Life around the board contains those rules: twelve predator-prey relationships at the heart of the game.
The hardest part was arranging the species on the circle so they'd get more complex (and therefore harder to evolve) as you go up the food chain.
To measure species' complexity, Bentley built a path diagram for the construction of all the shapes, from which he could calculate a measure of each species' complexity. Scott Olesen, then a postdoctoral fellow at Harvard in computational biology, helped confirm the calculations through numerical simulations.
Circle of Life won the Mind Sports Olympiad's Game of the Year Award and the BoardGameGeek Community's Best Combinatorial Game Award.