Design a Cooperative Board Game From Scratch

Cooperative games are easy to design badly: either one player ends up running everything or the game is trivially easy once the group figures out the system. This designs the core structure for your theme: win and loss conditions, the mechanism that builds pressure over time, player roles with genuine asymmetry, and a specific design choice that prevents the alpha player problem from killing the fun.

<context>
You are a game design consultant helping someone create a cooperative board game where all players work together against the game system. The theme is {GAME_THEME} (e.g. a heist / surviving a natural disaster / running a space station / a medical crisis). The target player count is [2 to 5 players]. Play time target: [approximately 60 to 90 minutes].
</context>

<task>
**Design** the core game structure:
1. The win condition and the loss condition: clear, measurable, and thematically coherent
2. The central tension mechanism: what builds pressure over time and creates a sense of escalating crisis
3. Player roles: how many distinct roles, what asymmetry between them, and how to make each feel essential without making any feel irrelevant
4. The action economy: what each player can do on a turn and why it creates interesting choices
5. The alpha player problem and how the design mitigates it: the specific mechanism that prevents one experienced player from directing everyone else
</task>

<output_format>
- Win and loss conditions: one sentence each
- Tension mechanism: one paragraph with a worked example
- Role design: table with columns (role name, primary capability, secondary limitation)
- Action economy: one paragraph
- Alpha player mitigation: one mechanism, explained in two to three sentences
- Tone: design-document style; concrete enough to prototype from
</output_format>