I hear that [the HERO System's] open-ended approach brought a sneer from an editor at a rival game company that publishes another universal system. "Look at this!" he said of the CHAMPIONS game's powers list. "The put pictures of magnifying glasses and stop-signs next to some of the powers to warn you that the powers are unbalanced! If they can't balance them, they should leave them out."
A reasonable point. But like the issue of reality vs. genre, it admits of two approaches. In the Balance-or-Die version, the game's designers try to imagine every combination of powers and situations, rule on them at length, and automatically veto any they've overlooked. They treat rules like the Food and Drug Administration treats medicines, requiring exhaustive testing to prevent consumer toxicity. Once balanced, the rules become Holy Writ, from which thou shalt not depart.
I know players who prefer this approach, perhaps for the sense of control and stability it produces. again, the CHAMPIONS rules take a different tack by shifting the responsibility for game balance from the publisher to the GM. The rationale is that in a system that allows desolidification, time travel, clairsentience, and a dozen other story-altered devices, it's up to each individual GM to choose not only the story but the ways in which the players can alter it.