Raid/attack events
Periodic threats assault the player's base or colony, forcing a shift from building to defense and testing whatever they've prepared. RimWorld's raids and They Are Billions' swarms punctuate the building loop with existential stakes: everything constructed since the last attack is on the line. Designers use raid events to give base-building purpose (you're not just decorating, you're fortifying), to pace the game with tension spikes between calm building phases, and to create emergent crisis stories. Key decisions: escalation scaling (RimWorld's wealth-based raid scaling ties threat to prosperity, discouraging turtling), telegraphing and warning time (enough to prepare, not enough to trivialize), attack variety so defenses can't be static, and the consequence of failure (setback versus wipe). Pitfall: raids that scale purely with time rather than player state either overwhelm slow players or bore fast ones; tying threat to the player's actual power and prompting active defense rather than passive walls is what keeps the tension meaningful across skill levels.
- Dev effort: Medium
- Timing: Real-time or turn-based
- Common in: colony-sim, survival, tower-defense
Seen in
- RimWorld
- They Are Billions