For further information, since this has me thinking about it again, the first thing I would ask players for is their paradigm.
Now, I'm not insisting that you write me an entire self consistent magical system, but I do want to know how your character approaches/uses magic, because that is what makes you as a faction unique and different then everyone else, as well as telling me what I should let you get away with. (Though of course, good arguments are always heavy weights on the scales.)
For example, I mentioned psionic space whales. Let's take a paradigm that could make those.
Random Player X uses the... let's call it 'Druidic Oversoul' paradigm. His or her character believes that all life is connected, in meditation and harmony with nature. He harnesses this deep connection with all living things to call upon the aggregated power of the entire ecosystem to achieve miracles with a trained will to focus it, and believes that all other living things can do the same.
So his system obviously uses living things to do magic, because only things can draw upon this deep connection. So you get whales, mutated and trained to call upon this power to swim among the stars instead of the waves, to amplify their sonar with their wills until it reaches from sound to gravity, forming a powerful sensor ability or focused to deliver shatter gravitic blasts. They use the power of their wills to twist space with awesomely powerful telekinesis to achieve superluminal travel, and tow cargo in telekinetically anchored containers. Perhaps they are specially evolved to have crews, or cyborgs.
Of course, obviously this paradigm could do a lot more things then space whales, like giant mutant coral passenger liners that ride the tides of solar wind and happen to use luminosity for self defense lasers.
But the paradigm still tells me the basics of how a player is going to play the game, and making everyone take their own (Or at least insisting that if people take similar ones they don't just copy each other.) makes sure that everyone is doing cool and unique stuff.
Because while that bio-paradigm is fun, with it's mutant teleporting giant wasps being based off of a symbiotic space tree for a carrier, it's still highly different then the paragram that summons elemental spirits, making giant flying submarines that swim through the elemental plane of water to take shortcuts in a realm where the speed of light can be sidestepped, which fires 'torpedoes' made from summoned and bound fire elementals, and with a protective sheath of lightning spirits serving as a close in point defense network.
(Hopefully people can see here how I took the 'Druidic Oversoul' paradigm and made three different ways people could make stuff from it... all from extrapolating from a single paragraph of how the magic worked for that player. You won't need an essay for paradigm, ideally, just a fair sized paragraph that gives you room to use your imagination)
I mean, when it comes down to it, everything is DM judgement calls. That's what a ruleset is - a bunch of pre-prepared DM judgements. If you want freedom, then you have to be willing to make on the spot judgement calls. Speaking as someone who's run a game heavy of DM judgements about tech interaction/strength for over a year now, the most important things is to be consistent and willing to admit that you've made a mistake.
You know, this is a fair point. And every time I bring up the game, people keep telling me to run it. It gets more tempting every time I remember this idea...
