Space Travel

In Eclipse Phase, space travel is largely a narrative thing. In Alternate Phase, however, space travel has been made (relatively) cheaper and easier, and therefore a system for rules for it, however shallow, is needed.

Gravitics and the Higgs Drive

The science of gravitics comes to transhumanity almost exclusively through the Fusers. Certain improvements have been made in specific areas over the years by non-Fuser transhumans, and most transhuman cultures are able to construct them on their own in 2501, even if not all of them fully understand the deeper mathematics behind the drive's operation.

A Higgsfield engine generates thrust by altering the curvature of local space-time, causing the ship to 'fall' in the direction of thrust. For observers on the ship in question, this feels much like any standard reaction thruster, in that the ship has a definite up and down. Most ships are therefore built more like office buildings than old sailing ships, especially those that spend most of their time under realspace thrust instead of in drivespace.

Almost all space habitats are constructed in the style of the Standford Torus or the O'Neill Cylinder, rather than using a Higgs field to generate artificial gravity. This is because this would generate thrust just like any other application of force, and would have to be corrected for with immeasurably complex counterthrust. It's simpler (and cheaper) to just use centrifugal force.

One constant that cannot be escaped is heat. A Higgs engine draws a tremendous amount of power and therefore creates a significant amount of waste heat. Unfortunately, space is not a very efficient radiator, and heat buildup can cause major faults in a ship under thrust.

Rules for Space Travel

In normal conditions, space flight in Alternate Phase can be handled in much the same narrative fashion as in Eclipse Phase. If nothing of real import is happening, there's no reason to clog things up by rolling dice constantly. Routine Point-A-to-Point-B starflight can generally be handled with "how hard are you accelerating?" and "how hard do you want to push your stardrive?"

Player characters being player characters, of course, that's not really enough for the sorts of situations they're likely to get into.


Ships are represented by Aptitudes, much like morphs. However, these aptitudes are as follows: Durability (DUR), Electronics (ELT), Heat Threshold (HT), Power (POW) and Thrust (TH).



  • Kinetic
    • Ship-mounted kinetic weapons are generally mass drivers, and little customization is possible or necessary. A successful hit with a mass driver does 2d10+8 damage.
    • Range is theoretically unlimited, but because mass driver slugs cannot change trajectory they are easily avoided at range. At a range of 1 shift, mass drivers suffer a -15 penalty; at 2 shifts, -30. Past that, they're effectively useless save against stationary targets.
    • A Mass Driver requires two Power units to operate.
  • Beam
    • Beam weapons are variations on the laser.
      • Visible Light - 1d10+5
      • Microwave - 2d10+5
      • X-Ray - 3d10+5 (Military Only)
      • Gamma Ray - 4d10+5 (Military Only)
    • A Beam emplacement requires 1 unit of Power per level of the weapon; that is, a Visible Light laser costs 1, Microwave 2, etc.
  • Seeker
    • The mainstay of space combat at range is the seeker, an autonomous projectile that accelerates towards its target and either fires munitions of its own from closer range or just rams the target. Seekers that fire mass driver projectiles do 2d10 damage. Seekers that fire beams do half the listed damage and persist two Action Rounds, unless doing so causes the seeker to self-destruct, in which case they do full damage but only get one shot. Seekers that do not self-destruct and are not shot down by defensive fire can attempt to ram the enemy vessel for 2d10+5 damage.
    • Seekers can also mount nuclear warheads, but unless these explode literally right on top of the target (in other words, achieve a Margin of Success of 60 or more) they do not deal any damage, but do generate a significant electromagnetic pulse. Most modern computers are optical in nature and shielded, so this rarely does more than interfere with communications; on the other hand, if the nuke does hit, it does 6d10+15 damage, enough to wreck almost any ship.
    • Seekers can also mount antimatter weapons, which are functionally similar to nukes except they hit for full damage on a MoS of 30 or better /and/ score an automatic hit on every ship in the target's shift with the equivalent of an X-ray Laser. Weaponized antimatter deployment is also extremely illegal and an interstellar manhunt for the culprits will ensue.
    • Seekers accelerate at 10g by default, as they have no need to consider the comfort of human occupants. Higher quality seekers can push this to 15g or even 20.
    • Seekers are launched by specialized mass drivers, each of which requires a single unit of Power to fire. Seekers contain their own power sources.
  • Plasma
    • Plasma weapons are exclusively a short ranger weapon, taking a -20 to skill tests at 1 shift and being useless beyond that. However, they do 3d10+5 damage and Heat Value, as the fusion torch tears up the hull and superheats the structure of the target vessel.
    • Plasma weapons require a fusion reaction, and starting these does not come cheap - these require 3 power units per emplacement to operate.


Sensor upgrades improve the Electronics aptitude for the purposes of observing the outside universe.

Support Systems

  • Cryogenic Facility
    • In case of emergency, or on long-term sub-light spaceflight, it may become necessary to place passengers and crew in cryogenic stasis. A single cryogenic facility costs a number of Power units equal to the Durability hardpoints assigned to it, and can handle five times that many transhumans. Bulk versions, more costly and designed for long-term storage (most commonly used on lighthuggers) are also available.

Power/Heat Control

  • Secondary Generator
    • A secondary generator provides additional power to the ship's various systems. Each secondary reactor installed provides an additional 5 power units, at the cost of 2 Durability hardpoints.
  • Battery Reserves
    • Reserves store a quantity of energy that can be called upon at need, though this drains the reserve. Most commonly, this is used to extend the range of starfalls. Each Durability hardpoint dedicated to reserves can provide 2 Power units, but must be recharged after these units are expended.
  • Heat Sinks
    • A system of additional heat sinks enables the ship to efficiently contain more heat than the basic design would normally permit. +10 to Heat Value.
  • Directional Radiators
    • Provided that the location of an enemy ship is know, it is possible to radiate heat in such a way that the enemy ship will be unable to observe the infrared signature. However, doing so halves the rate at which heat is radiated, and may not function in all environments (GM's call).

Engine Modifications

  • Acceleration Compensators
    • Also known as g-compensators, g-diffusers, or inertial dampeners, these devices decrease the amount of stress due to gravity on ship structures and personnel. Sadly, they are not yet efficient or fast-acting enough to protect transhuman personnel from sudden and massive changes in the force and vector of gravity, so high-gee maneuvering on a dime is still out of the question.
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