In Gears of War 3 for the Xbox 360, there are a lot of weapon skins you can unlock by performing certain tasks.
Some of these are retroactive from the previous games, and should unlock automatically if you met the criteria from that game.
Here is the list of weapon skins you can unlock, and what must be done to unlock them.
Skin Sets for Multiple Weapons (most of these are for the first five weapons)
Golden Omen Weapons – Reach Level 100 in Gears of War 3
Infected Omen Weapons – Included with the Gears of War 3 Epic Edition, Limited Edition Console, or Limited Edition Controller
Liquid Metal Black Weapons – Included with the Gears of War 3 Season Pass
Liquid Metal Green Weapons – Free promotion, not currently announced
Liquid Metal White/Ivory Weapons – Exclusive to Epic employees or those who are close friends with Joe Graf
Individual Weapon Skins
Chrome Gnasher – Complete the campaign in all three Gears of War games
Chrome Hammerburst – Get the Dirty, Dirty Horde achievement (complete 10 waves in Horde mode on any difficulty and map) in Gears of War 2
Chrome Lancer – Get the Don’t Hate The Player achievement (finish a ranked match with the highest score) in Gears of War
Chrome Retro Lancer – Get the Domination achievement (complete 10 different Co-op chapters with Dominic Santiago on any difficulty) in Gears of War
Chrome Sawed-Off Shotgun – Get any achievement in Gears of War for the PC
Crimson Omen Gnasher – Kill 10 enemies in Team Deathmatch
Crimson Omen Hammerburst – Survive all 12 waves in Beast mode
Crimson Omen Lancer – 12 + 2 XBL Gold Card promotion
Crimson Omen Retro Lancer – Survive the first 10 waves in Horde mode
Crimson Omen Sawed-Off – Complete five Arcade Campaign chapters in Co-op mode
Golden Gnasher – Unlock the Veteran Gear achievement in Gears of War 2 (reach Level 100 and win a match on each of the four “Snowblind” map pack maps)
Golden Hammerburst – Play during the first week of the game’s launch (September 20, 2011 to September 27, 2011). This weapon will also carry over from Gears of War 2 if you already had it
Golden Lancer – Play during the first week of the game’s launch (September 20, 2011 to September 27, 2011). This weapon will also carry over from Gears of War 2 if you already had it
Golden Retro Lancer – Unlocked only during the Gears of War 3 beta for getting 100 kills with the Golden Retro Lancer
Golden Sawed-off Shotgun – Get the Commando achievement in the original Gears of War by completing all acts on Insane difficulty.
Onyx Gnasher – Get the Onyx medal for the Gnasher by getting 6,000 kills with the Gnasher
Onyx Hammerburst – Get the Onyx medal for the Hammerburst by getting 6,000 kills with the Hammerburst
Onyx Lancer – Get the Onyx medal for the Lancer by getting 6,000 kills with the Lancer
Onyx Retro Lancer – Get the Onyx medal for the Retro Lancer by getting 6,000 kills with the Retro Lancer
Onyx Sawed-off Shotgun – Get the Onyx medal for the Sawed-Off by getting 6,000 kills with the Sawed-Off Shotgun
Team Insignia Gnasher – Earn the Onyx Veteran medal by playing in 400 matches
Team Insignia Hammerburst – Get the Gold Veteran medal by playing in 300 matches
Team Insignia Lancer – Get the Silver Veteran medal by playing in 200 matches
Team Insignia Retro Lancer – Get the Bronze Veteran medal by playing in 100 matches
Team Insignia Sawed-off – Earn the Onyx Veteran medal by playing in 400 matches
