I'm toying with the idea of alternate uses for Hit Dice, allowing players to spend hit dice to power other effects or abilities. Perhaps these could be represented by Feats. For example:

Feat - Forceful Strike: You summon the energy from within to add extra strength and force behind an attack. When you successfully attack a target with a melee weapon, you may spend one Hit Die to add extra damage to the attack. Roll your Hit Die and add the result to the total damage.

Feat - Arcane Recall: You center yourself and plumb the depths of your mind to recall some of your magical ability. Spend one Hit Die to regain a spell slot. Roll your Hit Die and regain one spell slot of a level equal to the result. You must finish a Short or Long rest before using this Feat again.

Feat - Trick Shot: You steady your nerves and enter a state of pure focus to pull off a near impossible feat. Spend one Hit Die to gain a bonus to your next ranged attack. Roll your Hit Die and add the result to your Attack roll. You must choose whether or not to spend the Hit Die before making your attack roll.

Feat - Inner Radiance: You call upon your faith in a time of great need. Spend one Hit Die to regain one Channel Divinity, or roll your Hit Die to heal yourself for a number of hit points equal to the result. You must finish a Short or Long rest before using this Feat again.

These are just ideas of the top of my head, and not play tested at all, but I feel like Hit Dice are a wasted opportunity for something cool.

It's a good idea. It also balances well but I'd add a clause to each one that the Hit Dice has to be from the relevant class -for example the spellcaster must roll the Hit Dice from their spellcasting class to regain the slots in that same class. This is so somebody multiclassing can't use a d10 to recover potantially 9th level spell slot (a second wish for the day!). I'd also make Warlocks unable to use this spellcaster one and give them something else since they get a limited number of slots and can already refresh all of them on a short rest plus have a higher hit dice value (IIRC).

I'd also consider one for Skills or Saving Throws - adding totals to skill checks to really succeed on a skill that you absolutely need to (so as a level 4 character you're not falling into a lava for an instant death that no spell bar Wish or True Resurrection can undo. It also still balances well - using your stamina towards this skill or feat but tiring you out so you cannot recover/heal as efficiently on a short rest. It's a gamble and a reasonable trade-off.

It also takes a Feat to gain these uses, instead of other feats or ability score increases. This again really helps keep it balanced.

Definitely gets a thumbs up from be. :)

Quote from Cyb3rM1nd >>

It's a good idea. It also balances well but I'd add a clause to each one that the Hit Dice has to be from the relevant class -for example the spellcaster must roll the Hit Dice from their spellcasting class to regain the slots in that same class. This is so somebody multiclassing can't use a d10 to recover potantially 9th level spell slot (a second wish for the day!). I'd also make Warlocks unable to use this spellcaster one and give them something else since they get a limited number of slots and can already refresh all of them on a short rest plus have a higher hit dice value (IIRC).

I'd also consider one for Skills or Saving Throws - adding totals to skill checks to really succeed on a skill that you absolutely need to (so as a level 4 character you're not falling into a lava for an instant death that no spell bar Wish or True Resurrection can undo. It also still balances well - using your stamina towards this skill or feat but tiring you out so you cannot recover/heal as efficiently on a short rest. It's a gamble and a reasonable trade-off.

It also takes a Feat to gain these uses, instead of other feats or ability score increases. This again really helps keep it balanced.

Definitely gets a thumbs up from be. :)