Over at the OD&D boards, jcstephens wrote: “What if spells were ‘alive’, in the same way as magic swords? Maybe there’d be several different versions, with Egos and alignments and goals. Possibly, they might even have rivalries and grudges.”
As a hopefully useful by-product of my addiction to the surreality of random dice rolls, I present the following table for determining the goals of a magic-user’s spells:
- Spell wants a spellbook all to itself. If this already true, it wants the spellbook illuminated, re-bound, gilded, etc. at a cost of 1d6 x spell level x 10 gp.
- Spell feels its current position in your brain & your possessions is insecure, and demands to be scribed onto a scroll that is given to a M-U who leads a less dangerous lifestyle.
- Spell falls in love with another randomly determined spell in the M-U’s repertoire. It will only be scribed into a spellbook or scroll that also contains its beloved, and will only be memorized when its beloved is also memorized.
- Spell hates another spell and will not co-exist with it in a spellbook, scroll, or M-U’s brain.
- Spell wants its M-U to go on a quest: spells cast on a target want to be cast on a particular kind of target (roll as if for a wandering monster), illusion spells want to view the reality of some obscure thing they can emulate, etc.
- Spell chooses a new, fancier name for itself and will refuse to be cast, memorized, or scribed for 1d6 days following any incidence of being referred to by its older and less grandiose name.
If I were to use these in a game, I’d probably roll for a spells’ goal at the point where it was acquired, and likely wouldn’t do so for every spell (maybe roll 3d6 for the spell’s drive, and worry about its goals only if the total equals or exceeds the magic-user’s wisdom).
I’d provide a stick to make the consequences of failing to cater to your spells’ whims (like introducing your favorite set of magical fumble rules, or increasing the likelihood of fumbles if you’re already using them), but balance it out with a carrot. This might be the nature of the spell itself – perhaps only the most useful and desirable spells have goals – or it might be giving ordinary spells an advantage, like a penalty to the saving throw against a spell that’s fulfilled in its desires.

Enticingly clever. :)
Although I haven’t read any for years, isn’t this how spells work in Terry Pratchett’s Discworld stories?
Yeah, in the OD&D thread linked above coffee says: ‘Reminds me of the Octavo, in Terry Pratchett’s “Colour of Magic”. There were ordinary spells, and then there was the Octavo, containing the eight great spells. One of them lodged in Rincewind’s mind, and as a result no other spell would stay there long. Rincewind theorized that they were too scared to stay.”
Mentioned In Dispatches. Cool!