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Episode 2: Deep Space Survival

by Christopher Robin Negelein

In the heroic action of the Silrayne Arc where heroes and villains can bend and twist reality while traveling between the stars, hard vacuum can happen when you least expect it. All it takes is a flying bullet hitting an airlock window in a damaged, leaky starship to have all hell (and atmosphere) break loose. 

So to keep everyone breathing while we patiently wait for the Master Technician’s Guide, we’ve gathered all of our current Esper Genesis resources for vacuum, hard vacuum and different environmental suits in one place. 


We’ve attempted to avoid some standard Hollywood myths while, at the same time, keep some of the more fantastical elements of heroic space travel. To accomplish this, we’re offering a few different cinematic takes on trying to survive in a both an atmospheric vacuum and the environment of deep space.

Atmospheric Vacuums

For a standard atmospheric vacuum (not in outer space), use the rules for suffocation as noted in the Basic Rules or Core Manual:

When a creature runs out of breath or is choking, it can survive for a number of rounds equal to its Constitution modifier (minimum of 1 round). At the start of its next turn, it drops to 0 hit points and is dying, and it can’t regain hit points or be stabilized until it can breathe again.

Harsher Rules: Optionally, you can put a harder spin on being exposed to such a vacuum with a mechanic representing a creature doing damage to itself by holding its breath. Their lungs start to rupture as the held air escapes to equalize the lack of pressure outside the body.  In this case, the character takes 10 (3d6) necrotic damage for each round in which they are suffocating or choking.

SA2-space explorer

Deep Space Vacuum

The hard vacuum of space is cold, like 2.7 Kelvin ( or -270.42 Celsius/ -454.75 Fahrenheit) cold. Use the following rules for character exposure to this punishing environment. Note: the rank 8 esper power, Space Walk also lists similar rules.

A creature exposed to the vacuum of space without adequate protection takes 10 (3d6) cold damage and 10 (3d6) necrotic damage at the start of each of their turns and immediately begin to suffocate (see “Suffocating” in chapter 8 of the Core Manual).

To make things slightly easier for players, you can also allow characters hold their breath for a number of rounds equal to 5 plus half of their Constitution modifier before suffocating.

Vacuum Suits

In Voices Beyond the Veil  (EGCC01-03, by Robert Adducci), stats for a vacuum and EVA suit are provided. They’re defined as follows:

Vac Suits

This bulky outfit is used when a creature needs to enter a vacuum. The suit has a built in oxygen supply and is chemically sealed. While wearing this suit you are immune to poison, disease, and environmental ambient cold and heat. In a vacuum the suit can be maneuvered by bursts of compressed gas from controllable jets.

Standard Model: This represents the standard suit seen around an open spaceport dockyard where mechanics and technicians spend hours floating in space while bolting on contraband weapons and sensors. The suit is too awkward for wearing armor either under or over the suit. The suit has 8 hours of breathable oxygen and 60 minutes’ worth of maneuvering propulsion. Propulsion provides a speed of 20 in zero-G.

Corporate Security Model: In the past, corporate and paramilitary units would buy surplus military power armor for potential zero-G combat where heavy armor was needed. But with the collapse of Deleron Corporation, cheaper Mecharoid AIs are flooding the market, making many of these suits available for purchase from grey market vendors in the underbellies of a number of space stations. Though these provide more protection than a standard vac suit,  the extra armor and weight come at a price in the speed and maneuverability. The suit has 6 hours of breathable oxygen and 30 minutes’ worth of maneuvering propulsion. Propulsion provides a speed of 15 in zero-G.

Standard Vac Suit

Armor (light), common

Base AC: 11

Stealth: Disadvantage

Weight: 10lbs

Cost: 5,000 cu

Corporate Security Vac Suit

Armor (medium), common

Base AC: 13 + Dex modifier (max 2)

Stealth: Disadvantage

Weight: 30lbs

Cost: 6,500 cu

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