Vacuum Resistance in RimWorld Odyssey (1.6) — 100% Threshold + Loadout Calculator
How Vacuum Resistance Actually Saves Your Crew in RimWorld
Reaching 100% vacuum resistance (or staying in a pressurized room) is the only reliable way to stop vacuum exposure in Odyssey. Anything below 100% only slows the timer.
Def-backed where available (RimWorld 1.6.4633 rev1266). Updated 2026-03-24.
| Situation | Fastest reliable answer | Why it works | Biggest catch |
|---|---|---|---|
| Odyssey (vanilla EVA) | Vacsuit + Vacsuit helmet (32% + 69% = 101%) |
Crosses the 100% threshold cleanly. | Not the best combat armor. |
| Biotech gene path | Vacuum resistant + sealed helmet (45% + 65–69%) |
Gene + helmet hits 100% while freeing the body slot. | Still need cold planning for long EVA. |
| Breathless build | Breathless (+100%) |
Solves vacuum exposure by itself. | Doesn’t solve temperature, burns, or combat. |
| Royalty implant route | Vacskin gland + sealed helmet (85% + 65–69%) |
Makes 100% easy while keeping combat kits. | Implant cost/opportunity cost. |
| “I’m in marine/cataphract” | Don’t trust it as immune (marine 30% + 67% = 97%) |
“Almost” still accumulates exposure over time. | Works in short tests → fails in real jobs. |
| Room says vacuum | Fix enclosure + pump + airlock discipline | Pressurization beats heroics long-term. | One leak can keep the whole room unsafe. |
Hint: 99% still hurts. The only “safe” number is 100%+.
Vacuum Loadout Comparison
| Example build | Total | Exposure? |
|---|---|---|
| Vacsuit + Vacsuit helmet | 32 + 69 = 101% |
No |
| Marine armor + Marine helmet | 30 + 67 = 97% |
Yes |
| Recon armor + Recon helmet | 30 + 65 = 95% |
Yes |
| Cataphract armor + Cataphract helmet | 30 + 68 = 98% |
Yes |
In 1.6+ Odyssey, most combat armor sets are close. The vacsuit set (or gene/implant stacking) is the clean “always safe” answer.
Vacuum Resistance Explained
- 99% isn’t enough → 100% stops vacuum exposure growth.
- Exposure grows faster in higher vacuum (full vacuum is “worst case”).
- Recovery is fast in safe air: 10% severity per second.
- Even if you hit 100% mid-EVA, severity only drops after returning to pressurized tiles.
dSeverity/dt = 0.02 * tileVacuum% * (1 - vacuumResistance)\n(Full vacuum = 100%, resistance is 0.00–1.00)\nAt 100% resistance: growth = 0.Stack Chart (Practical Offsets)
| Icon | Source | Vacuum resistance | Requires |
|---|---|---|---|
 |
Vacsuit helmet | +69% | Odyssey |
|
Vacsuit | +32% | Odyssey |
|
Marine helmet | +67% | Odyssey |
|
Marine armor | +30% | Odyssey |
|
Recon helmet | +65% | Odyssey |
|
Recon armor | +30% | Odyssey |
|
Cataphract helmet | +68% | Royalty |
|
Cataphract armor | +30% | Royalty |
 |
Vacuum resistant gene | +45% | Biotech |
|
Breathless gene | +100% | Biotech |
 |
Vacskin gland | +85% | Royalty + Odyssey |
Def note: marine/recon offsets come straight from the game’s XML (VacuumResistance in equippedStatOffsets, gated by MayRequire="Ludeon.RimWorld.Odyssey").
Starjacks are “vacuum solved, cold not solved” because they come with the Vacuum resistant gene by default.
How much vacuum resistance do I need?
Aim for 100%+ total vacuum resistance for true immunity to vacuum exposure.
Is 99% “good enough”?
No. It only slows exposure; it never fully stops it. Longer jobs still build severity.
Does marine armor stop vacuum exposure?
Not by itself. In 1.6+, marine armor (30%) + marine helmet (67%) = 97% → still exposure over time.
Why is my oxygen pump room still vacuum?
Usually: missing roof tile, non-airtight boundary, open door/traffic, or power loss. Fix the envelope first.
Are there any vacuum-safe animals?
In vanilla, it’s a tiny category. Some insects are effectively vacuum-safe (100% vacuum resistance), but most animals aren’t reliable EVA workers. Zone animals away from airlocks.
Do Starjacks need cold gear?
Yes. Their vacuum side is strong, but space cold is separate. Treat them as “helmet + insulation + short loops.”
Does 130% do anything extra?
For vacuum exposure: no. Once you’re at 100%, you already stopped severity growth.
Click to expand
| Date | Patch | Vacuum impact (high level) |
|---|---|---|
| 2025-07-11 | Odyssey + 1.6 launch | Vacuum/space systems become live. |
| 2025-07-29 | 1.6.4535 | Fixed diagonal wall vacuum leaks; fixed Breathless suppressing Vacuum resistant. |
| 2025-08-06 | 1.6.4543 | Fixed vacuum resistance stat caching issues and overlay problems. |
| 2025-08-28 | 1.6.4566 | Added vacskin gland; improved vac barrier + apparel behavior. |
| 2025-10-31 | 1.6.4630 | Fixed apparel using the wrong vacuum context flag. |
Vacuum Resistance (Wiki)
Vacuum Exposure (Wiki)