One problem with complex rulesets that offer various ways to get bonuses is that there's often a strong incentive to stack multiple bonuses up to potentially gamebreaking levels. Then, in order to keep things challenging, a Narrator would have to stack penalties to match — an arms race that could easily remove all sense of balance from the party.
With the addition of Expertise Dice, 5e's various kinds of bonus dice could easily fall into this pattern. Guidance, bless, bardic inspiration, expertise dice, etc. — they're each fine in isolation, but if added up, they could turn into boring guaranteed success (or so close as to make no difference).
There are various ways to solve this. One would be to unify all these disparate mechanics into one, so that instead of adding various dice, you're increasing the size of a single die. But even simpler is just to use the maximum of various rolls, instead of the sum. So if you had, say, Bless and Resistance and Bardic Inspiration, you'd roll 3 dice to add to the saving throw, but you'd only use the highest one. And any expendable resources — like Bardic Inspiration — wouldn't be used up unless that was the roll you ended up using.
This would be a simple change to explain, and it would open up space in game design for LU, because you could be less stingy with bonus-die-type effects without breaking the game.
With the addition of Expertise Dice, 5e's various kinds of bonus dice could easily fall into this pattern. Guidance, bless, bardic inspiration, expertise dice, etc. — they're each fine in isolation, but if added up, they could turn into boring guaranteed success (or so close as to make no difference).
There are various ways to solve this. One would be to unify all these disparate mechanics into one, so that instead of adding various dice, you're increasing the size of a single die. But even simpler is just to use the maximum of various rolls, instead of the sum. So if you had, say, Bless and Resistance and Bardic Inspiration, you'd roll 3 dice to add to the saving throw, but you'd only use the highest one. And any expendable resources — like Bardic Inspiration — wouldn't be used up unless that was the roll you ended up using.
This would be a simple change to explain, and it would open up space in game design for LU, because you could be less stingy with bonus-die-type effects without breaking the game.