The spells of a master of illusion magic, twisted beings from the Far Realm, or a powerful psionic adept on Athas. Adventurers confronted by any of these often find their minds assaulted by powerful psychic attacks. In most cases a mind can deal with the damage from these attacks. But, what happens when a psychic attack deals so much damage that it causes a mind to loosen (or completely lose) its grip on sanity?
This article provides rules for DMs to incorporate insanity effects into their games. It provides stats for temporary and permanent insanity, as well as suggestions on incorporating these effects into your game.
These options should fit well into any campaign, particularly one in the Dark Sun setting or one featuring creatures from the Far Realm. The more creatures there are doing psychic damage, the better chance there will be for insanity to come into play. Athas and the Far Realm provide many options. With that said, the diseases presented in this article can have some fairly severe effects on a character. As a DM, it would probably be a good idea to have a discussion with your players before adding these rules to your game.
What sets off insanity in an otherwise normal person? For the purposes of Dungeons and Dragons, the trigger is taking an excessive amount of psychic damage. But, how much is “excessive”? That amount will be different for each character, so you need a measure that reflects the resilience of each individual character’s mind. The Will defense represents a character’s resistance to mental attacks, and therefore is a good option to use as a yardstick. Specifically, insanity is triggered whenever a character takes an amount of psychic damage that is greater than or equal to their Will defense in a single turn. When that occurs the character briefly loses control and lashes out against anyone within reach, friend or foe. If they are unable to mentally resolve the damage, then they are afflicted with the first stage of Temporary Insanity. Some effects are the same for every instance of insanity. However, the specifics of insanity will manifest differently in different people. The Random Insanity table below provides six sample “psychoses” for your use. Feel free to add to or remove from the table. Tailor it for your group.
Going insane leaves a character’s mind vulnerable to further psychic attacks, as well as making them less resilient. Maybe they hear voices in their head that keep them distracted and prevent them from ever feeling completely rested. If the disease progresses, the voices go from a distraction to a constant low-level attack as the character is in a struggle with their own mind. They can keep it all together in normal interactions, but in times of stress (such as combat) when they have to shift their focus externally, their mind begins damaging itself. At this point insanity is still something that a character could recover from fairly easily, but if allowed to progress further the situation becomes a bit more dire.
Once the insanity has a chance to insinuate itself deeper into a mind it becomes permanent. At this point, on top of everything else, it turns into a struggle for a character to simply sleep. Even if they can sleep they might be plagued by horrific nightmares. Their health could begin to deteriorate and they might lose some of their effectiveness in combat.
Recovering from permanent insanity is no trivial thing. Characters suffering from the disease will still be functional, but too many failed saving throws after extended rests will make them fragile. Perhaps the DM offers a rare “Repair Mind” ritual that’s only known to high-ranking followers of Vecna. Maybe there is a talented psionic healer in a far-flung city who, rumor says, can cure this type of affliction…for a price. Or perhaps the insanity truly is permanent, and the only real option is an early retirement. Ultimately, it should be up to the DM and their players to decide how to resolve permanent insanity.
As mentioned, the easiest way to provide opportunities for the insanity disease to come into play is to have monsters doing large amounts of psychic damage. The Dark Sun Creature Catalog has several good choices. If you aren’t running a Dark Sun game, re-skin! Or re-flavor a monster from another source and change its damage type to psychic.
Throw in a twist on a trap. For example: A party is clearing a dungeon overrun with mind flayers. They stumble on a cage with what appears to be a human kneeling on the floor clutching his head. As they approach, they witness his final horrific transformation into an illithid. Seeing something like that would have to be deeply disturbing. Treat that event as a trap that was triggered by the party approaching. Have it do psychic damage, in a range that would threaten the party’s sanity, to every creature with line of sight. The same could be done for any event that a character would find horrifying.
As stated, you should discuss these optional rules with your players before incorporating them. But, in order to preserve a little of the tension, don’t reveal exactly what triggers affliction with these diseases. Also, be mindful of how often these rules come up in play. In most cases, you wouldn’t want them to come up so often that they become a huge disruption.
Finally, have fun with these effects! While there are mechanical considerations, a character’s insanity is truly going to come to life through roleplaying. For instance, a stalwart dwarf suddenly becomes claustrophobic. How will he react when the thought of venturing underground causes him to break out in a cold sweat?
Random Insanity Table