Wizard vs fighter, low level melee

[Doctor Despair]

Alternatively, the wizard could just cast defensively. With combat casting, the wizard could have as much as 4 ranks, a +4 from their con, and +4 from the class, leaving them with a 15% chance to fail their level 1 spell, or 10% chance to fail their level 0. A wizard with con maxed like this will have to sacrifice int (saves) or dex (initiative) however. It does save a level 1 spell that we would have used on mage armor, but it lowers our odds if the fighter goes first, so we probably save the feat slot.

DC 16

4 ranks, Combat Casting (+4), 18 con (+4) = 12 bonus

Relative roll needed to pass: 4

3/20 are fails, or 15%


Edit:
As is quoted in the post, the sample wizard here has 12 or 14 int, 16 dex, and 18 con. They could swap the dex and con, raising the fail chance on defensive casting to 20%, but I'm not sure if that's optimal in exchange for the initiative boost. It might be.

The 12 int is needed to get a bonus spell. It doesn't hurt us to have it that low, though, because none of the spells we use here scale with int, and we don't use abrupt jaunt. 14 int would give us two uses, and we have the stats to spare, so why not.