Firing Randomness is an attribute of Weapons that is one factor in determining how accurate the weapon is against a fixed point. Firing Randomness is a specifically defined value by the weapon, but is slightly difficult to predict the outcome of because its effect is amplified by Range. Essentially, the result of firing randomness is Maximum Deviation = k × Distance to target × Firing Randomness.
Every shot will land at the Maximum Deviation from the target or closer, where k is a constant. As such, a lower firing randomness makes for a higher accuracy. Units without a Firing Randomness value use 0 in that equation, and will thus always fire on course to hit its target.
Some units have a different value for Firing Randomness while moving than they do when still. The Mantis is one such example.
Keep in mind that Supreme Commander simulates each and every projectile in real time as it travels which leads to events not seen in other RTS' (such as strategic artillery unwittingly hitting aircraft). Even a weapon with zero firing randomness (and, therefore, theoretically perfect accuracy) may still not hit their intended target if:
- The weapon's turret prohibits it firing in that direction.
- Another unit gets in the way and takes the hit instead.
- The shot hits terrain. This mainly affects weapons with a low firing arc in rough or dense terrain. E.g. The Rhino: T2 Heavy Tank
- If the target is moving the shot may arrive too late, landing where the unit was instead of where it is. Factors that contribute to this are low muzzle velocity, long range and fast moving targets. Some weapons can track their targets and are not affected by this.