This article was first broadcast in Episode Fifty-Five on 2nd January 2019.
Ryu: Hi. Did you think I’d left?
Lennon: No, but…given the subject matter I thought for sure the Killer DM would show up.
Ryu: Oh, yeah, she knew about it but she said *ahem*
Killer DM: If I want my players to lose their minds and start crying in a corner I hardly need game mechanics to help.
Ostron: That…impression of her you do is getting uncanny.
Lennon: Anyway, Madness, right
Players’ mental state is not usually something D&D focuses on. There are a number of spells that can directly affect it, like Confusion or Crown of Madness that describe spell effects altering creatures’ mental states. Various adventures also have deranged or mentally altered NPCs for the characters to interact with, but very rarely does anything deal with the mental health of the characters. Unless players actively try to roleplay it, most of the time it seems like the chain of events is “Well, mates, we had a bit of a time trudging through that underground lair filled with re-animated zombies of the townsfolk we ate with last week but we’re done with that now. Real sorry about that girl you hit it off with Ranagorn, it was a shame how you had to set her on fire and all. Who wants mead?”
People who’ve played other RPG games, tabletop or otherwise, and particularly the ones that have a horror-theme such as the Call of Cthulhu series, are familiar with the concept of Sanity as a facet of each character. There are a few different ways it’s handled; in some cases there are effects that characters have to resist to avoid mental effects. In others there is a meter or a counter that tracks the player’s mental state and various effects can either reduce or increase it, with various effects occurring depending on how low or high it gets.
If you want to add a mental stability element to your games, you can borrow one of the systems used in other games or homebrew a custom one for yourself, but that requires a certain amount of playing around with game mechanics either way. However, assuming you don’t enjoy ripping apart rules and analyzing the minutiae of them like SOME people (Ostron), the Dungeon Master’s Guide has a solution for you. Two of them, in fact.
The first of them can be found on pages 258 through 260 of the DMG. The rules there suggest treating Madness sort of like a status effect. When characters encounter a situation where going mad is a danger, the DM has them make a saving throw (the book suggests Wisdom or Charisma as the likely stats to use). If the save is failed, the character suffers one of a variety of madness effects. Depending on the severity, the effects could last for 1d10 minutes, 1d10 x 10 hours, or until something cures the effects. Since the effects are determined by tables, we’re going to let Ostron talk about them.
The tables all base the effects on a d100 roll, and are related to how long the effects last. The short term table has 10 effects that mostly correspond to ones you might see from a low level spell, such as fear of a character or being compelled to attack the nearest creature. For the longer term madness, 12 effects are possible. Those are more debilitating and sometimes mimic spell effects like the Confusion or Antipathy spell, or impose wide-ranging disadvantage.
The long term madness effects add one of 12 flaws to the character. None of them have specific mechanics attached to them, instead imposing behaviors such as “I keep whatever I find” or “Being drunk keeps me sane.”
The DMG doesn’t specifically mention when the checks should be made, but it does suggest that certain spells would cause a roll on the madness table in place of the usual effects.
For example, you could alter the “Confusion” spell to roll on the short-term madness table rather than the table provided by the spell. Similarly, the Symbol spell creates a glyph that imposes certain effects on whoever triggers it. One of the options is insanity. The spell specifies behavior for insanity, but you could decide that the creature rolls on the short- or long-term madness table instead.
The madness tables are useful if you want some more variety or authenticity to certain effects, or for one-off bouts of potential mind-disintegrations, but some DMs might want to integrate mental health as an intrinsic element of the whole campaign and investigate the players’ mental health on a regular basis.
For those situations, the DMG recommends adding a new statistic. In addition to Wisdom, Charisma, Strength, and the others, you gain a new stat: Sanity.
The details are found on pages 264 and 265 of the DMG, but in short Sanity functions just like any of the other stats; assigned a number at character creation, from which an ability bonus is derived. What you do with it beyond that is entirely dependent on how much work you want to put in.
If you just create the statistic and let it sit there, you can have the characters make Sanity saves or checks as needed. The DMG has a few suggestions for situations when sanity checks may be needed (deciphering totally alien magic is an example). The score can be increased as part of the usual ability score increases every 4th level with a class, and the DMG suggests ways it can be integrated with the madness tables. Failing Sanity saves can obviously result in Madness table rolls, but it also recommends reducing a character’s sanity score by 1 every time they suffer from long-term or indefinite madness. The score can also be used to recover from those conditions.
Applying the score and the associated bonuses beyond that requires some homebrewing. Since it’s an optional rule, no class is proficient at Sanity saves. If you want to add that option, there are a few obvious places. One of the easiest is the Monk’s “stillness of mind” class feature; when they get that at 7th level it isn’t a stretch to grant them proficiency on Sanity saves. An argument could also be made for Knowledge Domain Clerics or Warlocks devoted to the Archfey getting extra bonuses for their sanity statistic. Warlocks with the Great Old One as a patron would also work well for proficiency on Sanity saves.
Another place where Sanity may come in to play is planar travel. Often, characters will come in to contact with entities and beings the likes of which they’ve never even dreamt of, and so a sanity saving throw could be useful there. One great example of this is on page 51 of the DMG, which talks about travel to the Shadowfell. There’s an optional rule entitled Shadowfell Despair, which says that once per day characters should make a DC10 Wisdom saving throw, or suffer one of the effects listed on the table, as the Shadowfell is such a desolate, despairing place that simply being there has a mental effect on people. Using the Sanity stat to make a DC10 Sanity saving throw would be a great way to combine these two optional mechanics.
Beyond that the sky’s the limit, but remember changes like this should be done with care. It would be very easy to over-complicate things if you start going full bore with creating new spells, skills, or even class archetypes based on the Sanity statistic. Players should be fully informed that the game is being modified and you as the DM should probably reserve the right to back off on changes if they prove game-breaking.
On the other hand, if you’re going to include Sanity as an ability score, you owe it to your players to make sure it matters. Since it’s one of their abilities, they would have weighed the consequences of putting a low or high score in. If someone decided their 16 deserved to go in Sanity and you rarely have them make a check or save, it’s going to be frustrating for that player.
However, if you’re confident of your homebrewing skill and are ready to impose mind-breaking situations on the players, you’re well on your way to seeing your entire party have a nervous breakdown.
Lennon: You know, that actually happened to me once
Ostron: People didn’t buff their Sanity score enough? Bad rolls?
Lennon: No, I mean they literally all had a nervous breakdown. I think it was something about the tea I served that day.
Ryu: Over-caffeinated players do tend to be on edge
Lennon: Nah. That’s what the electrodes are for.
Ostron: Well let’s head on over to the scrying pool and make sure our listeners still have their mental faculties.