If you've taken a look at how Spirit of the Century uses aspects, you probably have a good idea of where I'm going. If not, aspects in that game can be good, bad, or both. To use an aspect to your benefit, you spend a fate point and invoke it. You then get a bonus to your roll because of the aspect. If the aspect has a negative quality to it, you gain a fate point if you active the aspect to complicate your situation. The GM can also compel a negative aspect, activating it when he thinks it would make things interesting and awarding you a fate point for your trouble.
In Houses of the Blooded, John Wick goes one further and makes all aspects double edged; every aspect has both a positive and a negative side. He does this because of the specific theme of his game, but I'm taking this idea for my own system for very different reasons. By my reasoning, if aspects are both bonus abilities and flaws, they stand a better chance of seeing use in game. If I know my group right, they'll start by using the positive portions of the aspects first, but as they get more comfortable with the system in general and their own aspects in particular, they'll bring the negative side into play.
That's all well and good, but what do aspects do in Shadowitz? Since the game's core resolution mechanic relies on accumulating successes, the easiest thing to is to make aspects give bonus dice when invoked. Yeah, this will likely violate my 10 dice max rule, but I'm willing to be a little flexible. Besides, since aspects require the expenditure of something to use, they're more likely to be edges that the PCs pull out when they need something extra, so most die pools will still likely stay within the 10 die barrier. I'm going to say an invoked aspect gives you a bonus of 2 dice on the roll. That seems significant without rocketing the die pool numbers into the land of unreasonable.
On the flip side, when compelled, I'm leaving these ill defined mechanically. Instead of inflicting a mechanical penalty, I think it would be more interesting if the negative side of aspects had a role playing concept. This doesn't have to mean that negative aspects are irrelevant in combat, just that they have role playing applications instead of die mechanics. For example, in thinking of aspects for my current party, I have a couple of ideas already.
One character is a street sam played by a man with a particular love of the sacrificial last stand. It's manifested in many a game, and everyone is well aware of it. This player derives a special joy from plugging a doorway with his character and firing until his guns are empty and his body has gained 40 pounds of lead weight while he covers his teammate's retreat. Now, after he drops the rest of the team runs back into danger in order to retrieve him, which defeats the purpose, but that's a communication issue they're still working on.... One possible aspect for this character:
Runners, You Are Leaving!
- Invoke - Gain 2 dice for any combat action that obstructs the opposition from pursuing your teammates. Yes, this includes killing the pursuers.
- Compel - You'll cover your team's retreat, but won't be a part of it. Stand and fight for them.
- Invoke - Gain 2 dice when casting a combat spell with a range of touch.
- Compel - Your desire to fight in close overwhelms your sense of tactics. You must move to melee on your next action, abandoning cover and ranged combat options.