[Solar System] Overflow dice secrets

I haven't found any particular problem in allowing the player to burn as much overflow as he happens to have at hand; presumably he's paying something for having that overflow in the first place, after all.

However, the Secret of Weapon Mastery is a bit special in that it activates equipment ratings with those dice - while overflow spending is not limited, equipment ratings cannot be activated with complete freedom. I'd say that you can't activate the same equipment rating twice in the same sequence, for instance; I would also likely judge that you can't activate two equipment ratings from the same piece of equipment. Let's see... ah, I actually wrote about that in the book:

[quote source="page 25 of WoN"]The default effect of equipment ratings isn�t cumulative, but if a character has some crunch that makes several pieces of equipment sensible, then I allow each individual piece of equipment to be used once per check as long as the action makes sense in the fiction. The Story Guide might wish to lean on traditional fantasy RPG aesthetics in this, with single-handed and two-handed weapons, shields and such.[/quote]

So I suppose that if you had the Secret of Weapon Mastery and two weapons (or two weapons with the Secret imbued) that the character can actually wield effectively through the span of a single exchange, and you didn't activate either for any other purpose, then I'd allow you to activate both of them for Weapon Mastery. The opponent would take penalty dice equal to the sum of the two applicable weapon ratings (one from each weapon) that you chose.

I should note that the overflow dice mechanics are a prime example of the sort of design porn that is not at all relevant for fans of light systems. I do fully recognize that their inclusion and the problems I solve with this stuff are rather marginal for most. Secret of Weapon Mastery, for instance, is extremely situational as a pure matter of effectiveness unless combined with two or three other Secrets and a solid understanding of dice probabilities. I don't mind this due to how disdainful TSoY is about game balance and how it's supposed to embrace player freedom in choosing their own sweet spot in the amount of crunch and points of contact. What I'm trying to say is that if you're feeling uncertain about those advanced equipment Secrets, there's no reason to castigate yourself over it - just ignore them. If any player in the group wants to use them, learning how they work is their problem, not yours. Basic equipment ratings, Effects and perhaps a light dressing of simple imbuements are more than enough to reflect even strongly equipment-focused fiction satisfactorily without ever going into overflow mechanics.