Martial characters and rituals

[Korgoth]

I don't really mind that martial characters would have access to ritual casting, but I would like the mechanics to be based on one of the mental stats (how effective, how many you can know, etc.).

Cugel the Clever in Dying Earth, for example, is able to cast something like ritual magic if he has a tome to read from. Of course, he invariably messes it up and causes a ridiculous situation.

A chance for a martial character to botch the ritual would be nice.