In my current ruleset, characters stop gaining HP at level 3. From level 4 onward, they gain +1 Helpful every time they level up.
HP = 1/3 of Con
HP = 2/3 of Con
HP = Con
Helpfuls are a renewable resource. They replenish whenever the character gets a good night's sleep.
A player can spend Helpfuls to modify an ally's roll by an equal amount, up or down. There is no limit to how many Helpfuls you can spend at once, and multiple people can contribute simultaneously.
The only caveat is that you must have a feasible way to affect their ally's action.
- The fighter feints, helping the wizard land a hit on the orc.
- The wizard shouts a warning, and the arrow meant for the warrior's throat hits him in the shoulder instead.
- The fighter reaches up with his shield, catching the arrow like an outfielder.
- The rogue sticks out his foot while the fighter shoves the zombie hog.
The fiction doesn't matter too much. Let them be badasses.
Thieves get an extra Helpful for every template. Unlike other classes, Thieves can spend Helpfuls on themselves.
GLOG characters don't really get much more powerful beyond level 3. Instead, they get more versatile. Helpfuls fit this philosophy well.
+1 Helpful is comparable to getting +1 HP (since you can use your Helpful to reduce incoming damage by 1 point).
They are similar to getting +1 HP at each level, since you can use Helpfuls to reduce incoming damage by an equal amount. +1 HP is better at a single thing, while +1 Helpful is more versatile.
The biggest tweak over Luck Points (the previous incarnation) is that you can only use Helpfuls on other people, rather than yourself. This has a few effects.
- It helps higher-level characters keep lower-level characters alive.
- It encourages players to stick together. It hopefully fosters camaraderie, too, since players will be saving each other a lot.
- It works as insurance, insulating the player against a streak of bad luck. If a lot of bad luck befalls one player, the other players can dump Helpfuls to keep them alive.
- It gives players something to do when its not their turn. Hopefully, they'll be watching each other's rolls, looking for places where they can turn a miss into a hit.
I don't know if I want to put a cap on Helpfuls. I've never had a game where players had more than a handful.