Overview
Cytosis is a worker-placement game set inside a human cell. Players place flasks (workers) on locations within the cell to collect resources (mRNA, Proteins, Carbohydrates, Lipids, ATP) and use them to build enzymes, hormones, and receptors. Completed Cell Component Cards score Health Points. The player with the most Health Points at game end wins.
Components
- 1 double-sided game board (Base Game / Virus Expansion)
- 43 Cell Component Cards (10 Enzymes, 6 Protein Hormones, 6 Steroid Hormones, 5 Steroid Hormone Receptors, 5 Protein Hormone Receptors, 4 Additional Resource, 7 Detoxification)
- 66 Macromolecule Resources: 18 mRNA (black), 18 Protein (red), 15 Carbohydrate (green), 15 Lipid (yellow)
- 30 ATP tokens
- 12 Event cards
- 5 Goal cards
- 2 Grey Flasks
- 1 First Player Marker
- Per player: 4 Flasks (2-3 players), 3 Flasks (4 players), or 2 Flasks (5 players); 2 Transport Vesicle Disks; 3 Player Markers
- 7 Epigenetic Modification cards (advanced)
Setup
- Place the board (Base Game side) in the center. Separate macromolecule resources by color and ATP tokens into supply piles.
- Place 2 Grey Flasks on the Grey Flask area.
- Shuffle Event cards (remove 2 for 2-3 players, 1 for 4 players, none for 5 players). Place face down near the board.
- Place Goal cards face up (number of players + 1) above the board.
- Shuffle Cell Component Cards. Place 4 face up in the Card Area. Deal 3 to each player; each keeps 2 and shuffles 1 back.
- Each player places a Health Marker on 0. The most recently sick player is first player and receives 2 ATP; subsequent players receive 3, 4, 5 ATP (going clockwise). Each player also chooses 2 additional resources (any combo of ATP, mRNA, or Lipids).
Turn Structure
Each round has two phases:
- Phase 1: Flask Placement – Starting with the first player, going clockwise, each player places 1 flask on an available spot and immediately collects resources or takes the associated action. Continue until all flasks are placed.
- Phase 2: Event Card & Board Refresh – Retrieve all flasks, return Grey Flasks. Reveal and resolve the top Event card. Discard the leftmost Cell Component Card, slide remaining left, and refill from the deck.
The game ends after the last Event card is revealed; play one more Phase 1, then skip to scoring.
Actions
Collecting Resources:
| Location |
Effect |
| Nucleus (DNA Transcription) |
Receive 2 or 3 mRNA |
| Plasma Membrane (Glucose Transporter) |
Pay 1 or 2 ATP, receive 1 or 2 Carbohydrates |
| Mitochondria (ATP Production) |
Receive 2 or 3 ATP; or pay 1 Carbohydrate for 6 ATP |
| Smooth ER (Lipid Synthesis) |
Receive 2 or 3 Lipids |
| Free Ribosome (mRNA Translation) |
Trade any number of mRNA for equal Protein |
Purchasing Cell Component Cards: Place a flask in the Card Area, pay the ATP cost shown, and take the card into your hand.
Completing Cell Component Cards (multi-step process):
Enzyme Synthesis (Cytoplasm): Reveal Enzyme card, pay ATP cost, pay Protein resources (and Carbohydrate if required) from personal stock. Gain Health Points.
Protein Hormone / Receptor Synthesis:
- Rough ER: Place Transport Vesicle Disk on a budding location. Trade mRNA from personal stock for equal Protein from general stock; place Proteins on the Vesicle.
- Golgi Apparatus: Move Vesicle from Rough ER to Golgi. Add 1 Carbohydrate or 1 Lipid from personal stock.
- Plasma Membrane (Exocytosis): Reveal card, move Vesicle out of the cell, pay ATP cost, return resources to general stock, retrieve Vesicle. Gain Health Points.
Steroid Hormone Synthesis:
- Smooth ER (Steroid Hormone Synthesis): Place Transport Vesicle. Place Lipid resources on Vesicle per card requirement.
- Golgi Apparatus: Move Vesicle, add 1 Carbohydrate or 1 Lipid.
- Plasma Membrane (Exocytosis): Complete as above.
Alcohol Detoxification (Smooth ER): Pay ATP cost from card, gain 1 Health Point immediately.
Laureates in Biology (First Player): Take the First Player Marker and either take 1 ATP or place a Goal Marker on an available Goal card. First Goal Marker placed on each Goal card awards 3 Health Points.
Instead of placing a flask, a player may collect 1 mRNA, 1 Lipid, or 1 ATP and exhaust one flask (it cannot be placed this round).
Scoring / Victory Conditions
- When the last Event card is revealed, play one final Phase 1, then score.
- Health Points from completed Cell Component Cards (tracked on the Health Track throughout the game).
- Health Points from Goal cards (3 HP for first marker, plus end-game bonuses per card criteria).
- Event cards may grant or cost Health Points during the game.
- The player with the most Health Points wins.
Special Rules & Edge Cases
- Only 1 flask per spot; occupied spots are unavailable that round.
- If no budding Transport Vesicle locations are available (Smooth ER, Rough ER, or Golgi), the active player may remove another player’s Vesicle (and its resources) to free a spot.
- Transport Vesicle Disks and resources on them stay on the board between rounds.
- Grey Flasks are available for any player to use but are returned to the board at the start of Phase 2.
- Event cards may add bonus resources to locations; the first player to place on any spot within that location gets the bonus at no additional cost.
- A player must have at least the required resources on their Transport Vesicle, but may have more.
- Cell Component Card deck runs out: shuffle the discard pile to form a new deck.
Player Reference
| Resource |
Color |
Primary Source |
| mRNA |
Black |
Nucleus |
| Protein |
Red |
Free Ribosome (trade from mRNA) |
| Carbohydrate |
Green |
Plasma Membrane (costs ATP) |
| Lipid |
Yellow |
Smooth ER |
| ATP |
Token |
Mitochondria |
| Card Type |
Completion Location |
Key Resources |
| Enzyme |
Cytoplasm |
Protein + ATP |
| Protein Hormone |
Rough ER -> Golgi -> Exocytosis |
mRNA/Protein + Carb/Lipid + ATP |
| Steroid Hormone |
Smooth ER -> Golgi -> Exocytosis |
Lipid + Carb/Lipid + ATP |
| Receptors |
Rough ER -> Golgi -> Exocytosis |
mRNA/Protein + Carb/Lipid + ATP |
| Detoxification |
Smooth ER |
ATP only |
- Flask counts: 4 (2-3p), 3 (4p), 2 (5p)