D&D 5E Expanded Rules to Expend Hit Dice

[Frankie1969]

In the "What do you want in 1D&D" thread,

My requests:

• Warlord.
• [ . . . various others . . . ]
• more effects that use Hit Dice.

Here's some ideas for that last one.

1. To endure harsh environments, forced marches, lack of sleep, and other tiring situations, creatures need to expend Hit Dice, at a rate depending on the severity (ranging from 1 per day to multiple per hour).
2. Some creature abilities, poisons, and other effects will drain Hit Dice.
3. If a creature is out of Hit Dice but is required to expend them, they gain a level of exhaustion instead.
4. One level of exhaustion can be removed by expending Hit Dice equal to 1 + half your total Hit Dice (with a maximum of 4) after a rest.
5. Any spell that directly restores lost HP (as opposed to creating healing items or granting extra HP/THP) allows the recipient to expend up to one Hit Die to heal per spell slot level.
6. A creature who was dropped to 0 HP cannot remove the Incapacitated condition unless they expend a Hit Die (or gain a level of exhaustion).

p.s. The Warlord class should have abilities that expend or restore Hit Dice (both others & their own).
p.p.s. The DMG should include explicit written permission for DMs to rename Hit Dice "Healing Surges" at their tables, but only if they stop complaining about it.