Physical Tests
Arm-wrestling, lifting and jumping — derived from real biomechanics and real gravity.
One engine, every test
The same procedure that resolves a gunnery shot resolves an arm-wrestle, a lift and a jump. Nothing here is a special case.
Roll 3d6 exploding + Skill + Attribute, meet or beat the Target Number. Margin = Roll − Target Number.
| Difficulty | Target Number | Unskilled chance |
|---|---|---|
| Routine | 5 | 98.1% |
| Easy | 8 | 83.8% |
| Standard | 11 | 57.4% |
| Demanding | 14 | 35.9% |
| Hard | 17 | 21.0% |
| Severe | 20 | 11.4% |
| Extreme | 24 | 4.9% |
Opposed tests do not exist
An arm-wrestling match is not two rolls compared. It is one player roll against a Target Number derived from the opponent, so every die at the table stays in a player's hand and the Target Number remains a pure function of game state — which is what the Player Assistant needs to compute it.
Jumping: gravity is the whole story
Takeoff velocity is set by the jumper's legs and does not change with gravity, so distance scales as 1/g. This is the most dramatic environmental effect in the game.
| Body | g (m/s²) | Untrained | Trained | Powered armour | Vertical (trained) |
|---|---|---|---|---|---|
| Ceres | 0.27 | 61.8 m | 87.3 m | 132.4 m | 40.9 m |
| Luna | 1.62 | 10.6 m | 14.8 m | 23.0 m | 6.5 m |
| Mars | 3.72 | 4.8 m | 6.6 m | 10.6 m | 2.6 m |
| Spin hab (0.3 g) | 2.94 | 6.0 m | 8.3 m | 13.2 m | 3.4 m |
| Earth | 9.81 | 2.0 m | 2.7 m | 4.7 m | 0.7 m |
| Super-Earth (1.6 g) | 15.7 | 1.4 m | 1.8 m | 3.4 m | 0.3 m |
Low gravity is dangerous before it is useful
A trooper who jumps in a 2.4 m corridor on Luna hits the ceiling head-first at speed. And once distances pass roughly 20 m it stops being a jump at all — it is a ballistic hop, committed at takeoff, unsteerable without thrust, landing at takeoff speed, and a predictable target for the whole arc.
Lifting
Muscle produces the same force regardless of local gravity, so liftable mass scales as 1/g. Deadlift capacity for an 80 kg human:
| Training | Earth | Mars | Luna | Ceres |
|---|---|---|---|---|
| Untrained | 80 kg | 211 kg | 484 kg | 2907 kg |
| Lightly trained | 120 kg | 316 kg | 727 kg | 4360 kg |
| Trained | 160 kg | 422 kg | 969 kg | 5813 kg |
| Strong | 200 kg | 527 kg | 1211 kg | 7267 kg |
| Elite | 240 kg | 633 kg | 1453 kg | 8720 kg |
| World class | 320 kg | 844 kg | 1938 kg | 11627 kg |
The inertia trap
This is the physics science fiction gaming almost always gets wrong, and it earns a rule of its own. Gravity changes weight. It never changes mass.
| Cargo | Weight on Luna | Impulse to stop at 2 m/s |
|---|---|---|
| 50 kg crate | 8 kgf | 100 N·s |
| 200 kg crate | 33 kgf | 400 N·s |
| 400 kg crate | 66 kgf | 800 N·s |
| 1000 kg crate | 165 kgf | 2000 N·s |
The rule
Tests to lift or carry use weight, so gravity applies. Tests to start, stop, catch or redirect a mass use inertia and ignore gravity entirely.
A 400 kg crate on Luna weighs 66 kgf and lifts one-handed — but stopping it at walking pace still takes 800 N·s, roughly the impulse of catching a falling motorcycle. Low-gravity cargo handling is dangerous precisely because the first test gets easier while the second does not.