Exhaustion

Status Effect -> Stacks of Exhaustion:

1. Disadvantage on all ability checks. This includes initiative but NOT saving throws.
2. Speed halved
3. Disadvantage on all attack rolls and saving throws
4. Hit point max reduced by 1/2 of total
5. Speed reduced to 0
6. DEATH

More Info:

• Having 2 exhaustion stacks means, you also have all the effects of the previous stack(s) as well
• ONE stacks of exhaustion is removed after each LONG rest, also long as the PC is able to eat and drink
• (Exhaustion replaces lingering wounds from the DMG)
• ONE stack of exhaustion can be removed by a greater Restoration spell.

Combat Related:

• Critical hits cause 1 level of exhaustion on creatures
• Also you gain 1 level of exhaustion each time: You drop to 0 HP but are not killed outright
• Fail a death saving throw by 5 or more
• Massive Damage!!  When taking over 50% of damage to your total HP you MUST make a CON saving throw DC 15. Upon failure you take ONE stack of exhaustion.  This check cannot be made if hit by a critical hit, because the player already takes 1 stack of exhaustion from this; unless the player did not receive a stack from the critical hit due to some magical means (Adamantine Armor, for example), then a check is made.

Non-combat related:

• Not sleeping automatically causes 1 level of exhaustion
• Starvation can cause exhaustion (not eating for 3 days), or drinking any liquids for 1 day
• Forced March.  Any march beyond 8 hours is considered a Force March.  A DC 11 CON save is made, then increases by 1 for every hour, for every player.
• Any strenuous task done for a long duration without resting
• Traveling too long in the hot desert sun
• Stages of withdrawal from a potent narcotic
• A powerful artifact, but using it requires passing a save or gain a level of exhaustion
• Repeatedly using an unstable method of dimension-hopping

Sources: https://thealpinedm.com/dnd-5e-exhaustion/

Type

Physiological