Power Corrupts: Side Effects for Magic Users gaining levels

"This is Corruption"
Doug Kovacs 2011

On the internets today, my eye was poked by an awesome image by fantasy artist Doug Kovacs.  It masterfully illustrates a wizard passing through the various stages of his career and gradually changing as he becomes corrupted by his growing power.  This also rekindled my love of the old  AD&D 3 Stage Miniatures (of which I've written before).
 
Hack and Slash, Trollsmyth and Grognardia all write about spell casters gaining temporary side effects as a consequence of casting or memorizing the spell.  However, I feel that this would become onerous to track in game and doesn't really reflect the concept illustrated in the image, namely the chronic effects of exposure to thaumaturgic energies and their corrupting effect on the flesh and mind.

This is not a new idea,  in fact it's a defining feature in most fantasy literature, be it Saruman's corruption by Sauron or Raistlin Majere's racking cough and golden skin.  So why should there be a free lunch in RPGs? 

I can't think of a good reason not to to do this, so here's a little table of random levelling effects.

D20	DESCRIPTION	EFFECT
01	NOT YOUR DAY	Re-roll twice (ignore all results of 1 or 20) apply both effects, you retain the right of choice.
02	HAIR LOSS	The hair on your head falls out. You're permanently bald, deal with it.
03	MAGICAL BURNS	You have been burned by the thaumaturgical energies. Permanently lose 1 CHA, 1 DEX or 1 CON (your choice) which cannot be healed by any means.
04	ASTRAL SMOKE INHALATION	Your lungs have become scarred by smoke inhalation. Lose 1 CON permanently and develop a wracking cough which cannot be healed by any means.
05	DEFORMED SKIN	Your skin has become: scaley, changed colour, become translucent, become hairy, become leathery, developed warts or lesions, veined, liver spotted (you choose). This change is permanent and cannot be healed by any means.
06	DEFORMED EYES	One of your eyes has: changed colour, changed shape, become sensitive to light, or a particular spectrum of light, become bloodshot, enlarged. This change is permanent and cannot be reversed by any means.
07	DEFORMED HAND	You have, lost a finger or thumb, arthritis, paralysis, had your hand replaced by that of a beast, lost your whole hand (You choose).
08	SOUL TAINT	Your soul has become tainted and you have become less empathetic as a result. You permanently lose 1 WIS and 1 CHA which cannot be healed by any means.
09	VOID MIND	Part of your mind has been lost to the void. You permanently lose 1 INT which cannot be healed by any means.
10	DEFORMED FACE	You have: lost an eye, lost your nose, unexplained nose growth, lost your sense of smell or taste, developed facial scars, lost an ear, mishapen skull, lost teeth, developed fangs, facial droop, developed a wild expression (your choice). Lose 1 CHA permanently.
11	WITHERED LIMB	Your arm or leg has become withered (you choose). Permanently lLose 1 STR, 1 DEX and 1 Move which cannot be healed by any means.
12	HEARING LOSS	A magical explosion has permanently damaged your hearing and cannot be healed by any means. Lose all bonuses to hearing checks.
13	STOLEN YEARS	You have been permanently ravaged by Time. Add 10 years to your current age. This change is permanent and cannot be reversed by any means. You can never be rejuvenated below the age of 10. This effect can be taken multiple times and the effects of old age should also be applied as specified in the game rules.
14	STOLEN LIFE FORCE	Part of your life energy has been eroded. Lose 1 STR permanently. Cannot be healed even by magical or divine means.
15	SOUL CONTRACT	To save your own life you had to sign a soul contract. Your soul will be collected in 20 years unless you can find a way to break the contract. If you already have a soul contract it just got 5 years shorter.
16	SANITY LOSS	Your mind has become ravaged by the unspeakable horrors which lurk beyond this mortal realm. You permanently lose 1 WIS which cannot be healed by any means.
17	SIGHT BEYOND SIGHT	Everytime you look at someone: they age before your eyes, you see their death, you see their skeleton, you see their alignment aura, you see the face of a deceased loved one (you choose).
18	FRACTURED MIND	Your mind has become trapped straddling two universes. Whenever you are required to make a binary decision (Yes/No, Left/Right, Up/Down, Kill/Don't Kill) you must roll a d6 to determine your state of mind; 1-4 Your decision is unnafected, 5 You must change your mind to the opposite choice, 6 You become catatonic.
19	MALODOUROUS	You smell of: sulfur, stale urine, faeces, rancid milk, orc, a week old corpse (you choose). This change is permanent and cannot be reversed by any means only masked by strong perfumes.
20	GM'S CHOICE	GM rerolls and chooses the effect for you.

3 Stage AD&D Miniatures

(R to L): Citadel (ADD11) Female Wizard (Lvl 1)
Ral Partha (01-331) Illusionist (Lvl 2), Illusionist (Lvl 3)