Two Sets of Rules, the Good and Bad?

[GooeyChewie]

There's more to actions than number. Quality matters more: if PC legendaries don't contribute to e.g. decreasing enemy to 0 or making them unable to fight, it wouldn't really contribute to the problem. Stuff like active Perception checks and some item interactions could work great in the legendary framework for instance. Overall, it seems like a more functional out-of-turn action framework than the current Reaction framework.

Sure, quality matters. So does quantity. And sometimes sheer quantity begets quality.

Take the active Perception check, for example. If the DM builds an encounter where making an active Perception check does something important, then the Legendary Action allows the player to attempt that check while also doing whatever they want with their regular action. In this case, the quality of the Legendary Action isn't simply an active Perception check, but rather the quality of the other action the player took because they didn't have to use their regular action on the check. The Legendary Action takes away opportunity costs, which in turn means the players don't have to make as many meaningful choices.

On the other hand, if making an active Perception check doesn't do anything important, then the Legendary Action simply wastes time on a pointless roll. Either way, I don't see how Legendary Actions for players makes the experience better.

Wait...what? None of those apply. Legendary monsters aren't all equal, you don't fight them in swarms, and they don't change as they die (if they were fought in swarms).

I think the point is, if the DM were to build an encounter where you faced a swarm of faceless ninjas, none of them would have Legendary Actions. If the DM built an encounter where you faced one epic boss ninja (the last surviving ninja), that ninja would have Legendary Actions, even if they were ostensibly equally bad-ass as the rest of the ninjas.