The mishap table for the teleport spell violates one of the unwritten rules for D&D: a higher roll is better for the person making the roll. So I have reworked the table so the person teleporting wants to roll high (instead of the current version, where you hope for a low roll, in a flashback to 2E weirdness).

Update: At the suggestion of Gaël Zimmermann, I've changed the False Destination entry so it's not a faked d%-equivalent roll. The version presented below is statistically equivalent to the original d20+80.

Familiarity	Mishap	Similar Area	Off Target	On Target
Very familiar	--	01	02-03	04-100
Studied carefully	01	02-03	04-06	07-100
Seen casually	01-02	03-06	07-12	13-100
Viewed once	01-04	05-12	13-24	25-100
Description	01-08	09-24	25-47	48-100
False destination	01-40	41-100	--	--