Acceleration in Space

[Armitage]

When Star Hero first came out, I remember a discussion here about its use of velocity per Turn as a substitute for Gs of acceleration.

I recently put together a simple equation to determine the actual acceleration of a ship in space based on per Phase velocity.

It should be noted that, IMC, the maximum velocity of Flight is a product of mass, drag, structural integrity, etc. and only applies in atmosphere. Flight in space is Cumulative by default with a maximum velocity of 1.5x10^8" (light speed). This is balanced by the fact that if you spend two days constantly accelerating you can achieve a very high velocity, but it will also take you two days to stop. And, like MegaScale Flight, you will need pretty good long-range sensors. You can add the approximately +6 1/2 Cumulative Advantage if you want.

 

Acceleration per Segment=(V^2)/S

To determine acceleration per Phase, you then multiply by 12/SPD.

 

V is the ship's movement per segment. In most cases, this will be Combat Movement x (SPD/12). For Flight with Noncombat Acceleration/Deceleration, V will be Noncombat Movement x (SPD/12). For Flight with Rapid Noncombat Movement, V will be (Noncombat Movement/# of Doublings) x (SPD/12), as per the standard rules for determining movement per Phase with this Advantage.

 

For standard Flight and Flight with Rapid Noncombat Movement, S=Combat Movement/2.5. For Flight with Combat Acceleration/Deceleration or Noncombat Acceleration/Deceleration, S=2. For Flight with Combat Acceleration/Deceleration and Rapid Noncombat Movement, S=(Movement per Phase x 2)/Combat Movement.

The 2.5 value above is actually Acceleration per hex/2, so the Increased Acceleration/Deceleration Adder will add 0.5 per +1".

 

e.g. 20" Flight. SPD 4.

5.6" Acceleration per Segment, just over 1 G.

Adding Combat Acceleration, 22.2", just under 4.5 Gs

Adding x8 noncombat and Rapid Noncombat Movement, 39.5", roughly 8 Gs.

Adding x8 noncombat, Rapid Noncombat Movement and Combat Acceleration/Decelration, 59.3", almost 12 Gs.

Adding x8 noncombat and Noncombat Acceleration/Deceleration, 1422", almost 284.5 Gs.

 

Add in MegaScale and the numbers get even higher.

 

Obviously, this house rule would then require changing the damage from acceleration, otherwise, the last example would do 283d6 damage. I use a geometric progression, like other damage does:

2 Gs 1d6

3-4 Gs 2d6

5-8 Gs 3d6

9-12 Gs 4d6

and so on...

 

5 Gs is usually quoted as the point where a human passes out, so with this system, a person would be Stunned after 1 Phase and Unconscious after two.