Using the Space Navigation Skill

Now that we have new information about navigating the Solar System, how can players and Gamemasters use navigation in a game? First, only spontaneous maneuvers require the Space Pilot Skill. Planned maneuvers are entered into the vessel’s flight computer, which applies thrust as required, without further human intervention. Properly generating and entering a flight plan is the job of the navigator, and uses the Space Navigation skill. If a vessel’s navigator is a Non-Player Character, the Gamemaster is responsible for describing the flight plan, and deciding whether to make any Skill Tests. If the vessel’s navigator is a Player Character, the Player controlling the navigator PC should handle navigation. What follows is one possible procedure for roleplaying such a situation.

The Player is responsible for writing out the vessel’s flight plans and should follow the example on the previous pages. The only section required is the list of maneuvers. The Player Character’s Navigation Skill is tested against the Threshold of each maneuver in the flight plan to determine whether the maneuver is successful. If the flight plan was filed with a space traffic control center for verification and confirmation prior to its execution, the Skill Test for each maneuver receives a +2 bonus. If the flight plan was verified, any Fumbles are treated as Margin of Success 0 (an error or conflict was found and corrected, but not optimized). The magnitude of the Margin of Success, or Margin of Failure, is an indicator of how efficiently and accurately, or inefficiently and inaccurately, the maneuver was conducted. For instance, an MoS of 20% indicates success with a couple of course corrections required, but an MoF of 20% indicates that the maneuver was not quite successful and will require another maneuver to make corrections. A Fumble without STC verification is a serious matter that could possibly put the vessel in danger of collision, atmospheric drag effects, or a highly unstable orbit – whatever works out better for the adventure at the GM’s call.

Whether or not the Player or Gamemaster rolls the Skill Test is the GM’s decision. The following guidelines can be applied to Skill Tests and Thresholds to ensure a fair resolution of maneuvers. In general, relatively high (twice or greater) or low velocities (half or less) compared to the target body will modify the Threshold by +20% when establishing an orbit. In situations where the maneuverability of the vessel might make a difference, also apply half the vessel’s Maneuver Rating (round toward zero) as a bonus or penalty to the Skill Test. If the vessel’s engines are damaged, the resulting Maneuver modifier must be applied. A navigator can increase the chances of success by running simulations to check his results. For each simulation run prior to executing the maneuver apply a +10% bonus. Each simulation takes 15 minutes to complete per point of Threshold.

Maneuver Thresholds

Insertion into Orbit (10% + Vessel’s Velocity) /10, Round Up
Planetary Transfer 30%
Modify current orbital altitude 20%
Modify current orbital inclination 20%
New altitude and inclination 20%
Gravity Assist See following section on Spacecraft maneuvers
Aerobraking 30%*

*Threshhold for plotting course only; apply Mos as a bonus or MoF as a penalty to Piloting skill roll


Insertion into Orbit (Body’s Orbital Velocity-Vessel’s Velocit)x1d6 (non-negative value; minimum 1)
Planetary Transfer (Body’s Orbital Velocity x Body’s Gravity x 1d6) +20
Increase Orbital Altitude Body’s Gravity x Vessel’s Size x 1d6
Decrease orbital Altitude Vessel’s Size x 1d6
Modify Current Orbital Inclination Vessel’s Size x 1d6

*Must be applied over successive turns if vessel’s Thrust is less than required amount. Modify Piloting roll percentage by Navigation Test MoS (subtract) or MoF (add); minimum modified roll result of 10%

Using the Space Navigation Skill

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