One of your arms (the nondominant one 90 percent of the time — choose or roll 1d10 to determine) acts as if it has a mind of its own, not responding to your will and doing seemingly typical acts but inappropriately, such as picking up and moving objects, unbuttoning a shirt while you rebutton it with your other hand, knocking objects out of your hand, groping your body, etc. While out of your control, you cannot use it for any intended purposes. You must also make a Constitution saving throw every round to maintain spells. Spells with somatic components usually need to be modified to work within your physical range, requiring a day for every hour normally needed to inscribe into your spellbook and double the cost due to experimentation materials. In ten percent of cases, when the hand begins acting on its own, you must succeed on a DC 5 + (IE) Charisma saving throw, failure resulting in the hand being hostile toward you, attempting to choke or grapple you. In this case, you can resist the grappling as usual by succeeding on a contested Strength check against yourself. The GM should determine the hand’s actions, which may also require a contested Dexterity check if trying to knock something out of your hand.

Real-world Examples

Alien Hand Syndrome caused by brain tumors, aneurysms, stroke, neurodegenerative disease, or trauma.

Assistive Options

Binding the hand will keep it from causing damage but will eliminate being able to use it when it’s functioning normally. Allies assisting against attacks give you advantage on the checks.

Magical Assistance

Charm Person and related spells can affect the hand to bring it under control, although if you have Fey Ancestry or other resistance to being charmed, the hand will also have this resistance.

Your mouth dries out quickly, requiring you to drink 1 + (IE) times as much water as typical or experience exhaustion from Dehydration. You also need to take a sip of liquid before casting a spell with a verbal component or making a Charisma (Persuasion) check. If you can’t drink first, you need to succeed at a DC 5 + (IE) Constitution check. If you fail, the spell is not cast, or you have disadvantage on the Charisma (Persuasion) check.

Real-world Examples

Diabetes, Stroke, Thrush, Alzheimer’s disease, Sjögren Syndrome, HIV/AIDS

Assistive Options

Chewing on gum or some other soft substance can help. One piece will reduce the IE by 1 for 10 minutes. Spells with verbal components cannot be cast with gum in the mouth.

Some of your face is paralyzed (20 percent × IE), making it difficult to talk and use non-verbal communication with your face. You receive a penalty on Charisma (Performance) and Charisma (Persuasion) checks equal to the IE. This is typically permanent, but the player and GM could choose a magical cause that results in fluctuations.

Real-world Examples

Bell’s Palsy, Lyme Disease, Injury, Multiple Sclerosis, Ramsay-Hunt Syndrome, Guillain-Barré Syndrome, Moebius Syndrome, Melkersson-Rosenthal Syndrome, Stroke

Assistive Options

Because facial paralysis usually prevents the eye from blinking fully, you must use eye drops to keep the eye moist and likely need to monitor for drooling and keep a towel handy.