The Crossbow Slinger (3.5e Optimized Character Build)
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This is basically similar to the Western Gunslingers of old. But with crossbows.
All stuff from the core rulebooks.
 Game Rule Components
 Spells, Powers, Soulmelds, Stances, etc...
2 bags of holding and an armory's worth of crossbows.
Starting Ability Scores (Before Racial Adjustments): Dex 15 is the only necessity, otherwise build for a standard fighter Race: Human
Starting Racial Traits:
|Saving Throws||Feats|| Class
|1st||Fighter 1||+1||+2||0||0||2 Weapon Fighting, Quick Draw, Weapon Focus (Crossbow(light))|
|2nd||Fighter 2||+2||+3||0||0||Point Blank Shot|
|3rd||Fighter 3||+3||+3||+1||+1||Far Shot|
|4th||Fighter 4||+4||+4||+1||+1||Weapon Specialization (Crossbow)|
 Other Components
Buy two bags of holding. Buy a lot of crossbows. Load your crossbows with ammunition of choice. Fill these bags with your crossbows.
You get to dual-wield crossbows without the hassle of reloading them or wriggling the lever on repeating models. Basically, you enter combat, go "Oh no, an enemy!" and whip out two crossbows and unload them into your nemesis' face. Then you just drop them and whip out another pair when the next round comes. Quick draw makes pulling a weapon a free action, so if you continue adding fighter levels and gain even more off hand attacks, you can keep working them in no problem until you run out of crossbows.
 Munchkin-Size Me
<- Take it to the next level ->
 Side Notes
Include a couple longswords or other melee weapons in your bags, because crossbows don't make good melee weapons.
You'll want to target casters and other, weaker classes, because when it comes to melee you'll get torn apart.
 DM Counters
You can rule that being stored drawn reduces the crossbow's oomph and impose an attack or damage penalty on each shot. Also, you can rule that there's a percent chance a dropped crossbow breaks or is rendered inoperable, forcing them to go through a fortune in crossbows. According to the SRD:
If the bag is overloaded, or if sharp objects pierce it (from inside or outside), the bag ruptures and is ruined. All contents are lost forever.
Bolts are sharp objects. Loaded crossbows in the bag may fire from being jostled, bumping into each other, springs giving, etc. Give it a roll, with the chance going up a wee bit for each crossbow tossed in the bag. At some point, bad luck will ruin the bag.
<- Any other side notes that don't fit in the above sections. ->