10 And They'll Tell Two FriendsPlay in a co-op game with either an employee of Gearbox or someone who has this achievement
10 Ding! NoviceEarn level 10
10 Discovered Krom's CanyonDiscover Krom's Canyon
10 Discovered The ScrapyardDiscover The Scrapyard
10 Fully LoadedRescue enough Claptraps to earn 42 inventory slots
10 Paid in New HavenComplete 5 missions in the Rust Commons
10 Rootinest, Tootinest, ShootinestKill 5 Rakk in under 10 seconds
10 Speedy McSpeedertonRace around the Ludicrous Speedway in under 31 seconds
15 Careful, He BitesKill 15 enemies with the Hunter's action skill
15 Discovered Crimson Lance EnclaveDiscover Crimson Lance Enclave
15 Discovered Eridian PromontoryDiscover Eridian Promontory
15 Down in Front!Kill 15 enemies with the Soldier's action skill
15 Duel-iciousWin a duel against another player
15 Made in FyrestoneComplete all missions in the Arid Badlands
15 Master ExploderKill 25 enemies with explosive weapons
15 My Brother is an Italian PlumberKill an enemy by stomping on its head
15 Reckless AbandonKill 15 enemies with the Berserker's action skill
15 Truly OutrageousKill an enemy with the Siren's action skill
20 Ding! ExpertEarn level 20
20 Get A Little Blood on the TiresKill 25 enemies by ramming them with any vehicle
20 Made in New HavenComplete all missions in the Rust Commons
20 Weapon AficionadoReach proficiency level 10 with any weapon type
20 You call this archaeology?Apply an elemental artifact
25 1.21GigawattKill 25 enemies with shock weapons
25 Can't We Get BEYOND Thunderdome?Win an arena match
25 FacemelterKill 25 enemies with corrosive weapons
25 FenceSell 50 guns to a shop
25 Group LF HealerRescue a groupmate from death in a co-op game
25 PyroKill 25 enemies with incendiary weapons
25 There are some who call me...TimEquip a class mod for your character
30 Ding! HardcoreEarn level 30
30 There's No 'I' In 'Team'Complete 15 missions in co-op
35 DuelinatorWin a duel without taking damage
40 Ding! SleeplessEarn level 40
5 Ding! NewbieEarn level 5
5 Discovered Headstone MineDiscover Headstone Mine
5 Discovered Skag GullyDiscover Skag Gully
5 Discovered Sledge's Safe HouseDiscover Sledge's Safe House
5 Discovered Trash CoastDiscover Trash Coast
5 Paid in FyrestoneComplete 5 missions in the Arid Badlands
50 Ding! ChampionEarn level 50
50 Pandora-dog MillionaireEarn $1,000,000