That's exactly what I was thinking as well. I think the failure thing might ahve to be a requirement.
In fact, I wouldn't want to award it for examples that were trivial in any way. That is, the Flaw should be brought into stark relief by it's inclusion to count. I'd like to stay away from GM fiat, however.
Another way is to just say that it can only be done twice per session or something. That way the player will at least consider when to put it in. However, I'm afraid that this would just lead to players looking for less important rolls to use it on, instead of more important rolls.
Another idea is to base the reward off of the difficulty of the opposing sides Ability. Perhaps only when the opposition was as strong or stronger than the character would this count. Again, that would make it a sort of interesting "insurance" against loss. A hedge in the commodities sense.
Mike
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