What are the conditions of a Zero-G environment?

Question

The Heroes Handbook mentions "zero gravity" as a particular environment one might use Environmental Adaptation, under the Movement power, to counter, but doesn't seem to indicate what is involved in zero gravity movement. Was this defined in an official book?

Answer 1

In the Cosmic Handbook, on page 27:

Environmental Adaptation for zero gravity is very popular for characters. With it, they can operate without penalties in low- or no-gravity environments. Being adrift without gravity and with no sense of “up” or “down” can be very disorienting. This power solves those problems and allows characters to use appropriate movement powers (typically Flight) without limitations.

Moving without gravity is also an issue. In small spaces without gravity, a simple Acrobatics or Athletics check (DC 10) is enough to move at a reduced rate (use the climbing rates). A failed check means the character is disoriented and is Immobile and Vulnerable. A character attempting to move their full speed must make an Acrobatics or Athletics check (DC of 10 plus their Speed rank). On a failed check, the character slams into a surface and must make a Toughness check (DC 15 plus their ranks of the movement power used) to avoid hurting him or herself, as well as being Immobile and Vulnerable until the next round (or there’s a moment to recover, if the movement happens out of combat).

Characters with Environmental Adaptation (Zero-G), can use their Strength to propel themselves through such areas with ease as long as they have surfaces to push against. These characters are skilled at maneuvering in this fashion and move at a Speed value determined by their Strength. Thus, a character with Environmental Adaptation (Zero-G) and Strength of 5 can fling themselves along at a speed of 900 feet in a movement action in a zero gravity environment. They do not need to make an Acrobatics or Athletics check and succeed automatically.

This is similar to the text from the Core Handbook for 2e although, as usual for comparing the two editions, 2E was much more extensive:

Creatures in a zero gravity environment can move enormously heavy objects. As movement in zero gravity requires only the ability to grab onto or push away from larger objects, climbing and jumping no longer apply.

Most creatures find zero gravity environments disorienting, taking penalties on their attack rolls and suffering the effects of Space Adaptation Syndrome (space sickness). In addition, creatures in zero gravity are easier to rush than in other gravity environments.

• Space Adaptation Syndrome: A creature exposed to weightlessness must make a Fortitude save (DC 15) to avoid the effects of space sickness. Those who fail the save are shaken, and those who fail the save by 5 or more are also nauseated. The effects persist for 8 hours. A new save is required every 8 hours the creature remains in a zero-g environment. Creatures with the Environmental Adaptation feat do not suffer the effects of space sickness.
• Speed: While in a zero-gravity environment, a creature gains a “flying” speed equal to its base land speed, or it retains its normal flying speed (whichever is greater). However, this “flying” movement is limited to straight lines only; a creature can change course only by pushing away from larger objects.
• Carrying Capacity: A creature’s normal carrying capacity increases by 10 times in a zero gravity environment.
• Attack Roll Penalty: Creatures take a –4 penalty on attack rolls and skill checks while operating in a zero-gravity environment unless they are native to that environment or have the Environmental Adaptation feat.
• Modified Rush Rules: A creature affected by a rush attack is pushed back 10 feet, plus 10 feet for every 5 points by which its opponent’s Strength check result exceeds its own.
• Long-Term Effects: Long-term exposure to zero gravity conditions can cause serious problems when returning to normal gravity. A creature that spends 120 hours or more in a zero gravity environment takes 4 points of temporary Strength damage upon returning to normal gravity, which recovers at a rate of 1 point per day.