Combat has no initiative rolls. Each round follows the same five steps, and every crawler gets two Actions per round to spend on attacks, movement, Spells or Interrupts like Evade.
- Mob Action Declaration. The GM announces what the Mobs will do: movement, attacks and targets.
- Crawler Reaction Phase. Players can spend Actions on Interrupts, such as Evade, in response.
- Mob Attack Resolution. The Mobs’ attacks and Actions play out.
- Crawler Action Phase. Players spend their remaining Actions, in whatever order they like.
- Clean Up. End-of-round effects happen, everyone’s Actions reset, and the next round begins.
Surprise
Normally Mobs go first. If the crawlers get the drop on their foes, with Skills like Stealth or Ambush, they get a single free Action before the first round.
Evade
If you don’t spend an Action to Evade, attacks simply hit you. If you do, you roll separately against each incoming attack. A Natural 20 or Amazing Success on Evade gives you Advantage on your next attack against that Mob; a Major Fail exposes a weak spot and adds damage equal to the Floor Number.
Damage and your Health Bar
Your Health Bar has 10 slots. Rather than subtracting every point of damage, you lose Health when damage crosses the thresholds set by those slots. Resting in a saferoom restores it: a 2-hour Short Rest heals 5 slots.
Source: Rules for Survival, pp. 30–41.