The Embryo (Card) Game
A card game about cooperation, competition, and the strategies cells play during early development — built on our published research.
Created by Rafael Alkalai and Joshua De Guzman, Shakiba Lab.
The Idea
Cells in a body are supposed to cooperate. Mostly, they do — but after an embryo implants, something stranger happens: its cells turn on one another, and roughly a third of the epiblast — the tissue that will become the entire body — is eliminated in the process.
That's an expensive strategy. So why does the embryo pay for it? Our 2026 Nature Communications paper used evolutionary game theory to treat the embryo as a game board, asking what strategy the surviving cells are playing — and what the embryo gets in return.
- Abou Chakra M, Hislop J, Egilmez I, Alkalai R, Bashth O, Maheden K, Gundagathi A, Ebrahimkhani MR & Shakiba N. The embryo game uncovers hidden cell behaviours. Nature Communications 17, 7506, 2026.
How to Play
Deal the cells in
2 to 5+ players. Everyone gets 4 action cards (three to play, one spare) — and the group is given a target cell count to hit, based on how many are playing.
Play three rounds, in secret
Each round, everyone picks one action card face-down — no talking strategy — then all reveal together.
Hit the target exactly
Add up the group's contributions across all 3 rounds. Match the target exactly and the embryo is viable — everyone keeps the candy tokens they earned along the way.
The four action cards — add cells, hold steady, or take one away.
Full Instructions
Every rule, spelled out — setup, turns, scoring, and how a round ends.
Download the PDFPrintable Cards
Print, cut, and shuffle — everything you need to play a round at home or in the lab.
Download the cards