Skill rolls are required whenever a course is plotted. Standard die modifier for plotting courses between stars is -1 per light year unless the character has a star chart for that particular jump.
Having a star chart eliminates the modifier if travelling from charted jump point to charted jump point (q.v.).
Jumping to or from Deep Space
It is far easier to jump to and from star systems than it is to jump to and from deep space.
- Attempting to jump to a known system from a known system incurs no penalty
- Attempting to jump to or from an unknown system incurs no penalty except for the increased penalty for no star chart
- Attempting to jump to a known system from deep space incurs a -5 penalty
- Attempting to jump to an unknown system from deep space incurs a -7 penalty
- Attempting to jump to a precise point in deep space incurs a -10 penalty
- Attempting to jump from one point in deep space, to another point in deep space, incurs a penalty of -1
A ship must normally travel at least 30 million kilometers before they can jump. This represents the fact that it is much safer to jump once the ship is well outside of all other gravitational influences except the sun. A pilot can choose to jump sooner but this will affect both the astrogation roll and the pilot roll. Astrogation roll is at -1 per 5 million miles difference. Thus, -1 at 45 million miles, -2 at 40 million miles, etc. Piloting roll is at -1 per 10 million miles difference. Thus -1 at 40 million miles, -2 at 30 million miles, etc.
An Astrogation computer is required to plot courses. However, modifiers can be reduced with a good astrogation computer. Each level of astrogation computer reduces the modifier by 1. A computer with Astrogration-0 (minimum required) installed does not reduce the modifier at all. A computer with Astrogation-2 intalled reduces the modifier by 2. Astrogation computers can only reduce modifiers. They can never give a positive dice modifier.
Time Required to Plot a Course
Plotting a course takes 10 phases per total minuses, including those offset with an Astrogation program. In other words, the Astrogation program does not reduce the time that it takes to plot the course. It only reduces the minus after the course has been plotted. If the Astrogator has the Lightning Calculator talent, time is 2 phases per total minuses.
If urgency is an issue, the astrogator can reduce his Astrogation skill to plot the course faster. For every minus one he takes to his skill, he reduces the time by 4 phases. Minimum time to plot a course is 4 phases (2 phases with Lightning Calculator).
EXAMPLE: Sam has Astrogation on a 14 or less. His ship has a computer with Astrogation-2 installed and running. He is plotting a course from one system to another that is 3 parsecs away. 3 parsecs is roughly 10 LY. If he did not have a star chart for that route, then he would suffer a total penalty of minus 8 (-1 per LY, +2 for Astrogation-2 running on the computer) and it would take him 40 phases to plot the course. However, he does have a star chart so the penalty is minus 1 per parsec (total of minus 3), plus 2 for Astrogation-2 running on the computer. It takes him a total of 12 phases to plot the course.
There are many options available when making a jump.
Star Chart or No Star Chart - Jumping without a star chart incurs a penalty of -5 to astrogation rolls.
Jump Point or No Jump Point - Jumping from an established Jump point to another established Jump point incurs no penalty. Not using a Jump point incurs a -2 penalty. Thus, Jumping from an established Jump point to a non-Jump point, or from a non-Jump point to an established Jump point, at the target system is at -2. Jumping from a non-Jump point to a non-Jump point at the target system is a total of -4.
High Speed or Maneuvering Speed - If you jump at high speed where you accelerated all the way to the Jump Point, astrogation rolls incur a penalty of -1 while the pilot roll incurs a penalty of -2.
Quick Jumps - A ship must normally travel at least 30 million kilometers before they can jump. This represents the fact that it is much safer to jump once the ship is well outside of all other gravitational influences except the sun. A pilot can choose to jump sooner but this will affect both the astrogation roll and the pilot roll. Astrogation roll is at -1 per 5 million miles difference. Thus, -1 at 45 million miles, -2 at 40 million miles, etc. Piloting roll is at -1 per 10 million miles difference. Thus -1 at 40 million miles, -2 at 30 million miles, etc.
Normal Jump - If you are using a Star Chart, jump from an established Jump Point, and are at maneuvering speed, then both the whole maneuver is considered Routine and both the astrogator and the pilot gain a +3 to their die rolls. If everything is normal except that you are not using an established Jump point (but are 50 million km from gravitational influences), then the pilot still gets a +3 to their roll though the astrogator suffers the indicated penalty.
In the event of a failed astrogation roll, the ship makes the jump but does not end up at the intended destination. How far off course the ship ends up is dependent on how much they missed their roll by. In the case where the astrogator's roll is 17 or higher, 18 is still an automatic failure but the astrogator gets to roll again at -5. If the second roll is successful, they are considered to have missed their roll by one. If the second roll is missed, then they are considered to have missed their roll by 2. A natural 18 on the second roll indicates a catastrophic misjump.
Missed by One - The ship appears at the destination system, but missed the Jump point. Roll 3d6 x 10 to see how many million km they are from the destination world or Jp. For each 6 rolled, roll again and continue to add. Ex: A roll of 3 - 3 - 6 means that the ship arrived 120 km away from their destination and one more die is rolled. This die roll is a 6 which increases the distance to 180 million km and another die is rolled. The die roll is a 2 so the total distance is 200 million km away from the destination.
Missed by Two - As above except distance is 3d6 x 25.
Missed by Three - The ship appears 1d3 light years outside the destination system in deep space.
Missed by Four or More - Ship appears at another system within Jump distance. Treat as Missed By Two to detemine where in the system if it is an inhabited system. If another system is not within Jump distance, then treat as Missed by Three.
Natural 18 - If the astrogation skill roll is 17 or higher, then the natural 18 must be rolled on the second roll. Catastrophic misjump. The ship appears at some other system. The GM may choose or can roll a random system within 2d6 parsecs (roll again if a 6 is rolled).