Quote Originally Posted by NichG View Post
But a hybrid system could avoid [the weirdness of 'intentionally burning cards' to trigger a refresh]. Lets say you can refresh a hand of 7 cards once per something like a short rest. Whenever you are trying to do something that would require a roll, you can choose either to roll or substitute a card . . .
This is very strongly reminiscent of a diviner's Portent, except that you've given players more uses and made it into a core mechanic rather than just a class feature.

Like Portent, it has both offensive and defensive uses. Also like Portent, there's a potential for players to never use it offensively because they're saving it in case they need it defensively. (There's some potentially-unintended interactions where a high roll is good offensively for attacks and defensively for saves, unless you also rework saves to get rid of the defender-rolls aspect.)

Compare this to hit points. Hit points were added back in the very early days of the game to solve exactly this problem: they make it impossible for a character outside of very low levels to be felled by a single blow from a level-appropriate foe. Save-or-die effects intentionally bypass hit points. If you don't like that, the simplest (not necessarily best) solution is to just not bypass hit points. You could make Disintegrate deal damage and only reduce a creature to dust if it is already reduced to 0hp, etc.

I think the biggest difference between this expanded Portent and HP is that the former tempts players to get "greedy" by spending too much of it offensively and the latter tempts players to get "greedy" by pushing forwards despite it running low.