Imagine you have crafted the perfect horror themed D&D campaign. It could be gothic horror, Lovecraftian horror, or an all-out slasher fest. You know you may or may not make at least one of your players scream in terror or possibly pee themselves with fright. You want them to channel that energy into how they roleplay their character, but how do you manifest those effects mechanically in-game?
Thankfully, the Dungeon Master’s Guide offers rules to inflict madness on your players’ characters. The rules and tables for Madness can be found on pages 258-260 of the DMG. The section spells out how madness can be inflicted upon characters, whether it’s from a spell like contact other plane, from being in a hostile environment like the Plane of Pandemonium, or just from the events that happen around them.
The DMG breaks madness down into short-term, long-term, and indefinite madness. Each interval of time has its own table that the DM can roll percentage dice to determine the effect. For short-term madness, the effects can range from paralysis to uncontrollable laughing, screaming, or weeping. It can also cause the player character (PC) to experience hallucinations or attack anyone or anything within range. The most amusing effect can cause the PC to develop the urge to eat dirt or slime. Short-term madness lasts 1d10 minutes, but a couple of the effects end when the PC takes damage.
Long-term madness lasts 1d10 hours and has more severe effects. They range from compulsive behaviors like washing hands or counting coins to extreme paranoia. One effect causes the PC to have uncontrollable tremors or tics that impose disadvantage on attack rolls, saving throws, and ability checks involving Strength or Dexterity. They can even experience partial amnesia, forgetting anything that had happened before the effect took place. The best outcome for both short-term and long-term madness is that the PC simply falls unconscious.
The worst type of madness is indefinite madness. This doesn’t add an effect to the PC, it forces the PC to take on an additional flaw until cured. These flaws range from “Being drunk keeps me sane” to “There’s only one person I can trust and I’m the only one that can see this special friend.” Rolling 96-00 on the percentage dice results in the flaw “I’ve discovered I really like killing people.”
Madness can be cured on all levels, but it requires different levels of spells to do so. Short-term madness can be cured with a simple lesser restoration or calm emotions spell. Long-term madness can also be cured with lesser restoration, but if the madness was inflicted magically, a remove curse or dispel evil spell is required. Only greater restoration can cure indefinite madness.
So, now that you have the mechanics for madness, how do you get your players to buy into the effects and roleplay them? Make sure they understand before the game even begins that madness is possible. When the effect takes place, explain as best you can how their character is affected. Let the player determine how the effect will manifest. For example, if the PC is affected with uncontrollable tics, let the player choose the tic. If they roleplay their madness effectively and are entertaining, consider offering them Inspiration for their efforts.
With things like madness, it is easy to fall into stereotypical or offensive portrayals of mental illness. If a player seems like they’re going down this road with their roleplaying, let them know that they might want to adjust their performance to be a bit more respectful. If, for instance, someone starts yelling out curses as a form of a tic, you may want to have them tone that down. Also, be aware that some of your players might suffer from a mental illness that has a symptom that shows up on the effects table. Many folks who suffer from OCD may compulsively wash their hands, so if you roll that effect, I’d definitely choose a different one.
Adding Madness rules to your horror-themed campaign can lead to interesting and entertaining avenues for roleplay for your players. It adds to the drama and gives your players something tangible to add to the fear. But always be respectful of your players and avoid any effects that your players might suffer from in real life. So go out there and scare the ever-loving crap out of your players!