I'm looking for a feat that does the opposite of power attack, if one exists, in DND 3.5. A friend of mine is playing a rogue and would like to use such a thing in conjunction with sneak attacks. I couldn't find one, but the general gist of what I'm looking for is the ability to trade damage for bonuses to accuracy rolls. Does such a feat exist? If so, in what sourcebook? My collection is limited but I'd like to at least be able to look online.
Accurate Attack is in the Net Book of Feats (non-canon)
Accurate Attack [General, Fighter]
You can sacrifice one attack for greater accuracy on the next.
Prerequisite: Base attack bonus +6
Benefit: When making a full attack you may forgo all but the first attack to receive a +2 bonus to hit for each attack you have forgone.
Special: You can take this feat up to four times. Each time you take it after the first you increase the bonus for each attack sacrificed by 1 (to a maximum of +5).
Example: A 13th level fighter has three attacks in a round with base attack bonuses of +13/+8/+3. The fighter chooses to use Accurate Attack and make a single attack with a base attack of +17 (+13, +2 for each of the two tertiary attacks not taken).
A fighter may select Accurate Attack as one of his fighter bonus feats.
You may also want to consider Weapon Finesse, which allows you to add Dex bonus instead of Str bonus to hit - this will help if your Dex bonus is higher than your Str bonus (as is the case for most Rogues), but only for light weapons.
But this sounds like almost exactly what you're asking for:
(from Dragon Compendium)
You are skilled in finding your opponent's weakness and striking where it hurts most.
Prerequisite: DEX 13, Ability to sneak attacks
Benefit: When making an attack that would qualify as a sneak attack, you may take away any number of dice from your sneak attack damage and add a +2 circumstance bonus on your attack roll for each die reduction you make. You may convert as many of your dice from your sneak attack damage as you wish in this manner. However, if you make more than one sneak attack during a round and are using this feat, you must convert the same number of dice for each one.
D&D has a certain idea that heavier and more powerful attacks are less accurate -- less controlled. To an extent, that is true to real life experience. And if one can sacrifice control for power, Power Attack seems like it should have a complementary feat which allows you to sacrifice power for control.
As far as the rules as written go, there is not much.
You mentioned that your friend is playing a Rogue. That means that this feat, Precise Strike, may be very relevant to his interests. It is featured in Icewind Dale II, if you are familiar with that Black Isle D&D cRPG. Effectively, it allows you to sacrifice sneak attack dice for +2 attack bonuses.
Beyond that, I believe you have to move into the realm of Homebrew.
It seems fairly simple to make a homebrew feat for this. Power attack is as follows:
Power Attack [General] Prerequisite Str 13.
Benefit: On your action, before making attack rolls for a round, you may choose to subtract a number from all melee attack rolls and add the same number to all melee damage rolls. This number may not exceed your base attack bonus. The penalty on attacks and bonus on damage apply until your next turn.
To make a totally balanced equivalent, there only needs to be a few changes:
Precise Attack [General] Prerequisite Dex 13.
Benefit: On your action, before making attack rolls for a round, you may choose to subtract a number from all melee damage rolls and add the same number to all melee attack rolls. This number may not exceed your maximum damage output. The penalty on damage and bonus on attacks apply until your next turn.
Granted, this new feat is a homebrew, so it does not fit into the game seamlessly (is not a prerequisite for anything else, for example). However:
1: It's what you are looking for.
2: It's balanced and logical.
3: It's easy to remember and doesn't use weird mechanics.
The War Chanter 3 lets your allies reduce their AC in exchange for an attack roll bonus. Found in Complete Warrior; only useful for you if you can talk your bard into taking levels in it. It's a pretty cool PrC anyways—the capstone lets the bard give everyone within 60 feet the same BAB as that of the highest ally within that area. If one of you has Leadership this is definitely worth it.
The [Style] Feat Inlnidl School allows one to sacrifice their shield bonus to AC in exchange for half that as an attack bonus. Light weapons only, and it requires both Combat Expertise and Weapon Finesse. Found in Drow of the Underdark.
Knowledge Devotion might be a good feat for him if he has lots of knowledge skills (since he's a rogue, this would probably only be useful for Humanoids and whatever skill he chooses from Knowledge Devotion.) It gets him a bonus to attack and damage rolls based on a (free action) knowledge check, and is found in Complete Champion.
Reckless Offense lets you subtract -4 from AC and gain +2 on the attack roll, but it doesn't scale up so I don't recommend it. Found in the Expanded Psionics Handbook (it's also in the SRD).
Chosen Foe is found in Drow of the Underdark; you gain a +1 bonus to attack and damage against one foe, -2 on attack and AC against any others for the turn.
I can't think of any others at the moment; however, your rogue would probably appreciate a pair of Gloves of the Master Strategist. They cost 3,600 GP, are functionally identical to Gloves of Storing, and give true strike 1/day. They are found in Ghostwalk while 3.0 material, the book has been updated to 3.5. The only change to the gloves is that it should say 'faint transmutation aura' before the caster level.