In the Hero System, END is based on your CONstitution, and is a measure of how much personal energy. Your personal END reserve enables you to
- exert your STRength in useful ways like lifting a car over your head or punching the baddie into next Wednesday;
- use active Powers like Energy Blast or Killing Attack (depending on how you build them, of course);
- other active heroic stuff.
Here's a short explanation from +Ron Edwards 's Doctor Xaos blog:
"Which brings me to Champions the role-playing game, first published in 1981, and examining a crucial rules change for its 1989 fourth edition, written by a different set of authors.
In the earlier editions (1-3), the rule is that for every 5 points of strength or power used, you lose 1 point of Endurance. Granted, that value starts pretty high – typically 40 or more – but consider that one is typically slamming away with 50 or 60 point powers, or as a strength-based fighter, an equivalent amount. Just hammering away like that can drain you, and at 0 Endurance, further effort comes off your more crucial reserves and can knock you right out. There’s a periodic recovery during fights, and one can use actions to do it too, based on a value called Recovery, sensibly enough. In a relatively standard Champions fight of the early days, heroes had to strategize their heaviest hits against their energy reserves, ducking to recover every so often."
Of course, doing all this stuff means your spend your END like a resource. When you're down to zero, you can still exert yourself, but now it starts doing STUN damage to you, meaning you can knock yourself out by overexerting yourself.
"Which brings me to Champions the role-playing game, first published in 1981, and examining a crucial rules change for its 1989 fourth edition, written by a different set of authors.
In the earlier editions (1-3), the rule is that for every 5 points of strength or power used, you lose 1 point of Endurance. Granted, that value starts pretty high – typically 40 or more – but consider that one is typically slamming away with 50 or 60 point powers, or as a strength-based fighter, an equivalent amount. Just hammering away like that can drain you, and at 0 Endurance, further effort comes off your more crucial reserves and can knock you right out. There’s a periodic recovery during fights, and one can use actions to do it too, based on a value called Recovery, sensibly enough. In a relatively standard Champions fight of the early days, heroes had to strategize their heaviest hits against their energy reserves, ducking to recover every so often."
Of course, doing all this stuff means your spend your END like a resource. When you're down to zero, you can still exert yourself, but now it starts doing STUN damage to you, meaning you can knock yourself out by overexerting yourself.
The obvious downside to this kind of simulationist (or whatever) modeling of getting tired is the extra bookkeeping -- which is made even more fun with rules that deal with Recovery (I'll tackle that in other post).
However, there are a few reasons -- off the top of my head -- that my friends I used to put up with this extra in-game work (which becomes second nature after a while, anyway):
- Pushing: There's this rule that you can push STR or any Power that Costs END up to 10 points maximum, but you have to spend extra END in addition to the normal exertion. That means that you can get extra damage or extra movement, but trade in rapid exhaustion (or even knock yourself out) redlining your abilities. Very comic book-y.
- Pushing Stats: Did you know you can buy up abilities like INTelligence or COMliness with the limitation Costs END? Then means that if you choose to use these stats at a higher level, you gotta spend END to do it (special effects: activating alien secondary brain and sucking in your gut, respectively). But, because the rules say you can only push powers or abilities that cost END -- you can effectively burn END to become hyperintelligent or incredibly good looking for as long as you can pay the END (or endure the STUN damage once you've run out).
- "Free" Cost Discount: the END cost of a power used to be Active Points / 5. When 4th edition came about, this rule was revised to END cost = Active Points / 10. This halved the END cost, and immediately prompted my group to buy all their powers at 2x END cost, because they were already used to the spending of END at the old rate; instant reduction in power costs!
- Power Batteries: It's a nice way to model things like a battery of some kind: by creating something called an END battery (sort of an external END stat) that gets used up faster if you use it at full power.
- Nova Blasts: There are certain types of powers that will wipe you out if you use them -- maybe even cause you damage. Sort of like a wave motion gun for a super-hero, you can't use most of your powers after doing it. In HERO, you can buy that 'beyond normal campaign limits' power at 10x END cost or something similar (making sure that using it doesn't inadvertently kill you when you use it) -- it helps convince the GM that you won't use it that often.
- Temporary END Boosts: sometimes powers of heroes, villains, or the environment in a super-hero setting can boost your total END reserve, or increase your rate of END recovery. This means that you can operate at a higher power level for a short while (taking advantage of things like #1, #2, #4, and #5 as needed), but within certain limits.
But that's just me, and what I remember us doing -- what about the other HERO mechanics out there? What builds have you put together?