First I'll direct you here. It's a great article on thieves and what's important to them.
Halfling Crossbow Thief
Here's my first take on a ranged rogue for your Halfling. I ignored the short sword and went with dual hand crossbows. You don't want to try to focus on melee and ranged at the same time, choose one and stick with it. Both are viable, I just chose ranged because that's what I'm familiar with.
This build focuses on stealth and damage. Thieves don't have a whole lot of nova potential, but this build does it as well as it can. Use a ranged basic, Backstab, Sudden Bolt, and Action Point another ranged basic using Slaying Action to double up on the sneak attack damage.
Feel free to comment on what you like and don't like and I'll edit to accommodate.
====== Created Using Wizards of the Coast D&D Character Builder ======
Halfling, Thief, Cloaked Sniper
Halfling - Banned (+2 to Stealth)
FINAL ABILITY SCORES
STR 11, CON 12, DEX 24, INT 9, WIS 13, CHA 19
STARTING ABILITY SCORES
STR 10, CON 11, DEX 18, INT 8, WIS 12, CHA 13
AC: 29 Fort: 21 Ref: 30 Will: 24
HP: 89 Surges: 7 Surge Value: 22
TRAINED SKILLS
Acrobatics +21, Athletics +12, Bluff +16, Nature +13, Perception +13, Stealth +21, Streetwise +16, Thievery +21
UNTRAINED SKILLS
Arcana +6, Diplomacy +11, Dungeoneering +8, Endurance +8, Heal +8, History +6, Insight +8, Intimidate +11, Religion +6
POWERS
Basic Attack: Melee Basic Attack
Basic Attack: Ranged Basic Attack
Halfling Racial Power: Second Chance
Rogue Utility: Backstab
Rogue Utility: Tactical Trick
Rogue Utility: Ambush Trick
Rogue Utility: Acrobat's Trick
Rogue Utility: Cunning Escape
Rogue Utility: Sneak's Trick
Seeker Feature: Inevitable Shot
Seeker Attack 1: Grappling Spirits
Rogue Utility 2: Fleeting Ghost
Rogue Utility 6: Chameleon
Rogue Utility 10: Acrobat's Escape
Cloaked Sniper Attack 11: Sudden Bolt
Cloaked Sniper Utility 12: Unseen Shot
FEATS
Level 1: Crossbow Expertise
Level 2: Backstabber
Level 4: Silvery Glow
Level 8: Slaying Action
Level 10: Two-Fisted Shooter
Level 11: Wintertouched
Level 11: Lasting Frost
Level 12: Primal Sharpshooter
Level 14: Primal Eye
ITEMS
Frost Hand Crossbow +2 x1
Frost Hand Crossbow +3 x1
Feytouched Inix Leather Armor +3 x1
Bracers of Archery (heroic tier) x1
Gloves of Ice (paragon tier) x1
Assassin's Cloak +3 x1
Eagle Eye Goggles (paragon tier) x1
Frozen Whetstone (heroic tier)
====== End ======
Optimal Crossbow Thief
Here's an optimal ranged build for Matt. The drow gets two big advantages - Ruthless Hunter (gives you d8 [W] damage and high crit) and Merciless Killer (+5 damage against bloodied targets). Everything else is pretty much the same.
====== Created Using Wizards of the Coast D&D Character Builder ======
Drow, Thief, Cloaked Sniper
Occupation - Criminal (+2 to Stealth)
FINAL ABILITY SCORES
STR 11, CON 12, DEX 24, INT 9, WIS 13, CHA 19
STARTING ABILITY SCORES
STR 10, CON 11, DEX 18, INT 8, WIS 12, CHA 13
AC: 29 Fort: 21 Ref: 30 Will: 24
HP: 89 Surges: 7 Surge Value: 22
TRAINED SKILLS
Acrobatics +19, Athletics +12, Bluff +16, Nature +13, Perception +13, Stealth +23, Streetwise +16, Thievery +19
UNTRAINED SKILLS
Arcana +6, Diplomacy +11, Dungeoneering +8, Endurance +8, Heal +8, History +6, Insight +8, Intimidate +13, Religion +6
POWERS
Basic Attack: Melee Basic Attack
Basic Attack: Ranged Basic Attack
Drow Racial Power: Cloud of Darkness
Rogue Utility: Backstab
Rogue Utility: Tactical Trick
Rogue Utility: Ambush Trick
Rogue Utility: Acrobat's Trick
Rogue Utility: Cunning Escape
Rogue Utility: Sneak's Trick
Seeker Feature: Inevitable Shot
Seeker Attack 1: Grappling Spirits
Rogue Utility 2: Fleeting Ghost
Rogue Utility 6: Chameleon
Rogue Utility 10: Acrobat's Escape
Cloaked Sniper Attack 11: Sudden Bolt
Cloaked Sniper Utility 12: Unseen Shot
FEATS
Level 1: Crossbow Expertise
Level 2: Backstabber
Level 4: Silvery Glow
Level 8: Ruthless Hunter
Level 10: Two-Fisted Shooter
Level 11: Merciless Killer
Level 11: Lasting Frost
Level 12: Primal Sharpshooter
Level 14: Primal Eye
ITEMS
Frost Hand Crossbow +2 x1
Frost Hand Crossbow +3 x1
Feytouched Inix Leather Armor +3 x1
Bracers of Archery (heroic tier) x1
Gloves of Ice (paragon tier) x1
Assassin's Cloak +3 x1
Eagle Eye Goggles (paragon tier) x1
Frozen Whetstone (heroic tier)
====== End ======
Optimal Melee Thief
This build focuses on charging and knocking things prone to get double attacks. Also note the synergy between Unbalancing Trick and Sneak in the Attack if you don't have the combat advantage to use sneak attack yourself.
====== Created Using Wizards of the Coast D&D Character Builder ======
Human, Thief, Kulkor Arms Master
Human Power Selection Option: Heroic Effort
Tomb Robber (+2 to Stealth)
FINAL ABILITY SCORES
STR 14, CON 11, DEX 24, INT 9, WIS 13, CHA 15
STARTING ABILITY SCORES
STR 13, CON 10, DEX 18, INT 8, WIS 12, CHA 11
AC: 29 Fort: 23 Ref: 31 Will: 23
HP: 88 Surges: 6 Surge Value: 22
TRAINED SKILLS
Acrobatics +19, Athletics +16, Bluff +14, Dungeoneering +13, Insight +13, Intimidate +14, Perception +13, Stealth +21, Thievery +19
UNTRAINED SKILLS
Arcana +6, Diplomacy +9, Endurance +7, Heal +8, History +6, Nature +8, Religion +6, Streetwise +9
POWERS
Basic Attack: Melee Basic Attack
Basic Attack: Ranged Basic Attack
Human Racial Power: Heroic Effort
Rogue Utility: Backstab
Rogue Utility: Acrobat's Trick
Rogue Utility: Unbalancing Trick
Rogue Utility: Ambush Trick
Rogue Utility: Cunning Escape
Rogue Utility: Tactical Trick
Rogue Utility 2: Sneak in the Attack
Rogue Utility 6: Swift Parry
Rogue Utility 10: Counter-Step
Kulkor Arms Master Attack 11: Arms Master Challenge
Kulkor Arms Master Utility 12: Tempered in Blood
FEATS
Level 1: Nimble Blade
Level 1: Light Blade Expertise
Level 2: Backstabber
Level 4: Cyclone Warrior
Level 6: Weapon Proficiency (Battleaxe)
Level 8: Kulkor Battlearm Student
Level 10: Wintertouched
Level 11: Deft Blade
Level 12: Lasting Frost
Level 14: Silvery Glow
ITEMS
Frost Rapier +3 x1
Badge of the Berserker +3 x1
Horned Helm (heroic tier) x1
Bracers of Mighty Striking (paragon tier) x1
Gloves of Ice (paragon tier) x1
Siberys Shard of Merciless Cold (paragon tier)
Feytouched Inix Leather Armor +3 x1
====== End ======
