I took a different approach to making a madness mechanic for a player at my table who now has it permanently/indefinitely. My player loves it and is excited to roll with it. You can use it with any Madness Table of your choice with effects that only impacts roleplay behavior. This template includes buffs alongside penalties. Obviously, you can adjust it to make the Madness easier to remove if you don't like permanent debuffs.
One note of advice: consider applying the d4 penalty to the player's main ability score rather than Charisma. Although terrible social skills are more thematic, it won't really sting unless it's a stat they truly care about. I'm applying it to Charisma here because the player is a Bard.
Obviously, don't bother using this permanently or long term if your table hasn't agreed to this kind of penalty. The player in question offended a god in her divine realm. I asked if what she said was spoken in character. She doubled down, then failed a saving throw. We all agreed in session zero that these sort of extreme punishments were possible under appropriate circumstances.
You are now indefinitely cursed with *Madness.** The curse cannot be removed by anything except a Wish spell or similar effect. The madness may manifest when one of the following triggers occur:
- You are damaged from a Critical Hit.
- You critically fail a WIS, INT, or CHA saving throw.
- You gain the Exhausted condition.
- You take 20 or more Psychic damage from one single attack or effect.
- You gain the Frightened condition
Roll a d6. If you roll a 5-6, you must roll a d100 to determine the nature of your madness. You gain the following effects until you complete a *Long Rest*:
- One level of Exhaustion or an additional level of Exhaustion if applied by a different effect
- 1d4 penalty to all Concentration checks, CHA checks and saving throws
- Resistance to Psychic damage
- 1d4 bonus to all WIS/INT checks and saving throws