So let's reconsider this as a bolt-on to any other RPG - a way of amending the ruleset to define a new style of play.

1> The Call is a different way of thinking about what makes hereos into heroes.

Characters gain an additional stat indicating their ability to carry "fate." Most people have no ability: a zero. A few ordinary people have a single point - they're the folks who rise to the occasion spectacularly in plane crashes and wars.

This single point has two effects: firstly, it can be spent to change the flow of narrative reality in the direction this person wants. The earlier the decision is made to expend the point, the greater the effects. As a rule of thumb, if used *after* damage is done, it can be reduced by 50% or otherwise mitigated, but if expended before, it can allow for narrative rescripting - the assasin's gun jams and the characters catch him as he flees, say.

Secondly, tests can be made against that single point as if it was a trait or skill: a success causes weird flows of coincidence which draw the character forward towards their fate or goals. The difference between "fate" and "goals" is game-dependent - sometimes they're the same, sometimes they're directly opposed.

2> Player characters have a LOT of call
PCs start with four to six points of call - a huge amount of resilience and potential. This has two effects:

Firstly, they're excessively hard to kill, as fate flows around them and they reroll dice, duck obstacles and perform near-impossible feats because their fate demands it. As a result, Call-driven games will throw beginning characters into much higher level and more dangerous scenarios than one would expect, as characters trust to their luck - their fate - and not their sea of hit points and arete.

Secondly, characters have no escape from The Great Game, as Kipling would call it. You go home to your father's castle or your underground lair, but the story follows you there. The Call Points which cause minor weirdness in the life of a 1-point-hero cause shattering revelations like "Your uncle Bilbo's Ring is the One Ring and now you're going to die unless you kill Sauron, shortie!"

Rolls get made. Every time you pass, more weirdness builds up. Fate will find you out.

3>NPCs, monsters and scenarios all have independent Call
Nazgul, say, have a *lot* of Call. Boatloads of it, in fact. Unless you've got enough Call to somehow survive, they're going to ride up beside you, spend a point, and skewer you like a duck without even going to the combat mechanics of whatever game is providing the physics engine to your story. Call can also be unbound - a "free pool" which is attached to a situation, so that anybody interacting with the situation can wind up "drafted" and have both Call and Mission dumped on them: in short, you can get "Called Up" as it were.

Examples are the regular henchmen of powerful opponents, who - one one hand - tend to be Keystone Cops most of the time as Players use their Call to fob them off - but occasionally they show up with Call of their own, and Indiana Jones and his father get snapped up by the Nazis. The regular footsoldiers find themselves protected by the Call of their leaders, as the fate of their leader intertwines with their own personal fate. Something similar can be seen in a lot of war stories where for a single hour a young man becomes exceptional, a bright and burning god, until the ridge is taken and then they're never quite the same again.

A Call Pool for something like The Lord of The Rings could run to thousands of points on both sides with figures like Gandalf having twenty, thirty, fifty points personally available.

GMs, obviously, have the ability to pull in arbitrary amounts of Call from these sources to combat the wiles of the Players. Don't.

4> Gaining - and losing - Call
There are two exists from the life of the hero: death, and victory.

Oh, and there's the one we don't discusss - failure, corruption and defection. Three exits.

Call is gained by not using it - by being victorious in a scenario and, at the end of the day, having the individual expenditure of Call be less than the Game Master's expenditure of Call. GM spends 15 points, three players spend 2, 2 and 4, and that's a big win. Games with a competitive streak might award Call only to the player who used the least, or vote who was the most skillful in use. Other games would level up the team as a whole. This is genre specific, I think.

Call is lost by two routes: acting like an anti-hero and messing up one's missions by using Call for personal purposes and by wildly, foolishly overspending. Those who keep doing this gradually lose call until they're fragile little mundanes again, unsuited for heroic activity by virtue of having burned out their luck. The doors of fate no longer open for such as these.

Players can rapidly gain Call, both by picking up points in association with a scenario ("10 point pool to defeat the Nazis holding the Arc of the Covenant") and leaders who have a lot of Call ("Gandalf spends two points of his call to save Frodo by having Eagles come.")

Note there's a fuzzy line between personal call and scenario call. Perhaps all personal call came from a scenario, or from a leader's call. This is an area where the game's metaphysics matter. Call of Cthulhu demands that players have no personal Call, but can draw from a pool dedicated to saving Humanity from the Other. D&D assumes players have a lot of personal Call and might pick up a point here or there from Kings and Gods and Quests. In Vampire, perhaps all call flows down hill from Cain or the Antedeluvians.

5> Call Challenges
Call has four uses.

* Call Rolls: roll against Call, if you pass, the scenarios bends in minor ways to pull you forwards. Roughly equivalent to a Skill roll like "Library Science." Not useful for combat or climbing, only for spotting things, coincidental events and so on.

* Call Challenges: Call vs Call rolls made around critical events like fights, jumping chasms and so on. These are challenges because the Bad Guys Fate is that you fall to your death, and your Fate is that you make it. These Challenges can only be called when the regular rule set suggests there's a non-zero chance of the Hero succeeding; the minimum threshold would vary from genre to genre but 10% might be a reasonable level. Players should only be able to Challenge this way a number of times equal to their current Call level in a given scenario. Bad Guys can also use these dynamics to save themselves or inconvenience players!

* Call Point Expenditure: heavy, heavy manipulation of plot or circumstances. Players get bushwhacked by goons and two die in the first volley: Call Points are spent, and those are now simply serious wounds. Players *need* to get in and out of the Library without getting caught - well, spend a point to buy a successful run. Note that the more consistent with ordinary probabilty and the current narritive thrust, the more change a single point can buy. Early spending produces new narritive - late spending simply fudges game dice.

* Call Point Duels: if two parties get into a skirmish and both want to spend Call to control the outcome, points may be bid against each other auction style. This is to be avoided where possible: the player bidding more winds up with an *incredibly* strong effect because they just spent five points of Call to outbid Mordor's four points - but loses their abilty to spend Call Points for any purpose for the rest of the session or scenario. (Alternatively, they can still spend to save their live, or other players can spend personal points to bail them out.)

6> Call Point Magic
A point or more of Call can produce effects which are outside of the magical physics of the game system being used. Characters pulling stunts like this without well-defined in-game narratives have to expend all the call they have. Others may be able to get away with it for less. A good example would be a Warewolf showing up in a hard-boiled detective fiction game: it's pushing the narrative around with a two-by-four but, if it's scenario-appropriate, it could be driven by these dynamics more easily than tweaking the rules.

7> Call Point Attrition - Ooops
These rules imply that nothing bad happens until one side is entirely out of Call Points. However, once the "real world" situation has turned against a player or a foe, the odds are that they're going to burn through their Call extremely quickly "putting out fires" while the other team's grand strategic plans unfold. Sauron with 10 points left over at the end of LOTR simply has the Hobbitses fall into the hands of the Nazgul, game over.

So, what do you think? Is there something here worth writing up more formally and playtesting a few times?

Sounds like a good idea. Is this at all inspired by Joseph Campbell's Hero Cycle (from "The Hero with a 1000 Faces")?