Inherent attributes of the character are called statistics. Some statistics are always active, like the ability to call single. Others are reactive, such as hits - you spend hits when you get struck with damage. No statistics can be tapped or sacrificed, but some can be burned - this will be made clear on each statistic.
The basic capabilities of each character are:
While some skills purchased with XP make changes to your statistics, most will instead grant you powers. A power has a limited number of times it can be used per encounter. Using a power is always a conscious choice, so cannot be done while you are incapacitated, dead, stunned, or under any other such effect. Powers can be used in three ways: they can be tapped, they can be burned, or they can be sacrificed.
The normal way to use a power is to tap it, which may require striking a target with a weapon or doing appropriate roleplay. When you have tapped a power, it is exhausted for the rest of the encounter, and so cannot be tapped again or sacrificed, although it can still be burned. All powers which have been tapped will refresh at the end of the encounter (or every 10 minutes in interactives).
Examples:
Purchasing a skill with XP will only let you use the power once, but you can buy more levels of it for progressively more XP and get more uses like that.
Once a power has been tapped, it is exhausted for the rest of that encounter. If you decide the situation is an emergency, you can however burn it. When you burn a power which has already been tapped, you get another use of whatever it gives you. However, you then become unable to use that skill until you have rebought it with more XP.
Examples:
For some powers, there is also an option to sacrifice them. This essentially combines the previous two options: to sacrifice a power, it cannot have been tapped yet this encounter. If you choose to sacrifice a power, it will be permanently disabled exactly as if it was burned, and you will get a more powerful effect for it.
Examples:
There's then some skill trees, hits and wounds, and a few other bits to go on this, which I'll add up at a later point.
This is currently quite sketchy, despite looking fairly definite. Main things which might change: xp or time or something else as the cost for burning or sacrificing. How many uses you get from burning.
Suggestion from Inquisitor, dumped here from IRC: Spending xp is (to my mind) an undesirable resource. Instead, charge people risk. An example of how this might work: They start the linear with a bag of beads. One red, nine white. Each time they burn an ability, they get a single extra double-strength use of it, and add a red bead to the bag (not instantly, just before they next draw from it). Presuming the existence of some sort of 'and stay down' coup de grace mechanic, whenever someone is picked up from a CdG?, they must draw a bead from the bag. If it's red, suffer a bad effect (possibly death, possibly something ref-assigned, whatever).
You could also have "tap" or as "lose per encounter" and "burn/sacrifice" as lose per week/day/event" depending on timescale. --Jim
Hm, I wonder about regain one burned ability per subsequetn full encounter. So burn something, lose it next encounter, regain it for hte one after that. Burn two things, and you're missing two of them for the first encounter, one for the second. And so on. --Tea