As a magic nerf, what if most spells took until the beginning of your next turn to cast? So, you start to cast
sleep in round 1, and then you have the entire initiative pass and complete the casting right before your turn in round 2. You're still casting spells once per round, but now there's a larger window of interruption or reaction, and the fighters get to fulfill the (apparently desired) paradigm of being necessary to protect the wizard. Magic can still be awesome, but this might contribute to making fighters
necessary, which is something they aren't currently.
I'd think we still need to make fighters individually more awesome though. Another minor thing we could do is let fighters lose that -20 penalty to maintaining a grapple while doing anything else. I like the idea of a fighter keeping some enemy in a headlock while hacking at some other dudes with his weapon.
For a non-combat travel power, what about something like an
Exhortation of Swiftness -- Anyone travelling with the fighter may use their natural Run speed for overland travel, without suffering any negative effects, provided they remain within 100' of the fighter. This speed increase applies to mounts as well.
That would need tightening up on the rules wording, but the idea would be that the fighter allows a group to travel faster than magical flight, can extend this speed increase to more people, doesn't cost them anything, and doesn't affect enhanced speeds. It would provide a choice in travel methods for parties, and allow them to potentially do things that magic couldn't easily replicate. This sort of thing would help get the refugees to Helm's Deep or march reinforcements to the front, as opposed to allowing a small strike team to bypass terrain or simply teleport to a location.
edit to add: The Exhortation of Swiftness power could level up to Secret Paths, which allows the fighter and friends to travel up to 10 x Survival Check result in miles per day and eventually allows planar travel, as others have suggested before.
Also, some additional semi-serious ideas:
You could also have the powers of
I Know a Guy, which lets the fighter pull some Deux Ex bullshit to move or push the plot every so often; and
I Planned on This, which lets him pull necessary things out of his pants. Party is stuck and can't find the info they need? The fighter Knows a Guy. They never found the password for the secret door? The fighter Knows the Doorman's Sister, and got if from her. The party gets DM captured? The fighter Planned on This and stashed equipment. He also Knows a Guy and planted a mole in the guard rotation.
These abilities could then upgrade to
The Fucking Cavalry, which produces your level in CR-2 allies as backup; and
Two Steps Ahead, which lets you negate some of your opponent's abilities with minor exposition.
These eventually combine into
Fortune Favors...Well, Me and the fighter can, once per level, just declare shit like an unknown great uncle leaves him the deed to a fortress, that a tribe of Hill Giants venerate him as the tiny reincarnation of their beloved leader, or that the Faerie Queen grants him the Timeless Body effect because he's too awesome to let age spoil.
