Vanguard: the Jump Drive

I thought about coming up with some nifty name for it, but really, jump drive is a simple, accurate name that won't overnerd anyone who worries about a space adventure game being too techy.

The jump drive allows instant movement between two places, much like the FTL drive on BSG, but with a few lightweight, easy limitations.

1) Gravity mucks up the drive. The closer you are to a big mass like a planet, the shorter the jump. Once you're within about a hundredth of a gravity, it won't work at all. You need regular rocket-style engines to operate close to a planet. When gravity drops low enough, your jumps go from the AU scale to the LY scale.

2) It takes a while to charge up. If you jump into trouble, you can't just hit the button and jump back out. It takes a few minutes to charge up the capacitor banks.

3) Plotting a course can be tricky when you jump farther than your instruments can see. Charting a new route probably requires shorter jumps and some tedious work.

From a gaming perspective, I think it's kind of friendly. The GM can technobabble the exact formula and draw maps that measure distance in jumps instead of km or AU or whatever. "Mars is two jumps away. Jupiter is 3 jumps from Mars." A D&D style gamist GM can create "encounters" along jump points where the ship drops in and needs to recharge and get its bearings. Pirates attack! A sandbox GM can create some detection and pursuit rules -- assuming a jump creates crazy electromagnetic radiation, hostile ships within a few light minutes might be able to detect your jump and jump after you before you can recharge.

It feels vaguely like age of sail to me as well. You have the void between worlds where nothing happens and you probably don't encounter any ships, and then you have star systems which feel more like the Caribbean with battles near the islands. Pirates camp out along established routes and watch for the flash of a jump, then swoop in.