Complete the following achievements to unlock Xbox Live Gamerscore points.

Achievement	How to unlock
Been There, Won That ( 10 points )	Win 1 Ranked Multiplayer Match of each Type.
Cerebral Assassin ( 10 points )	Get 10 headshot kills in one Ranked Multiplayer Match.
Double Time ( 10 points )	Complete any chapter after Arrowtree in Co-op on any difficulty
Dumb Luck ( 10 points )	Kill 5 enemies at once with explosive damage.
Emblematic ( 50 points )	You or a Co-op partner collects 20 Emblems.
Explosive Expert ( 30 points )	Kill 3 players at once with Trip Mines in a Ranked Multiplayer Match.
Finders Keepers ( 30 points )	You or a Co-op partner collects 10 Emblems.
Found It! ( 10 points )	You or a Co-op partner collects 1 Emblem.
Free Style Walker ( 15 points )	Chain together any 3 physical abilities in 5 seconds or less.
Have Gun, Well Traveled ( 20 points )	Win 1 Ranked Multiplayer Match on every Map.
Let's Go Streaking ( 20 points )	Win 10 straight Ranked Multiplayer Matches.
Pacifist ( 20 points )	Make a Flag Capture in a Ranked Multiplayer Match without firing a shot or using grenades.
Pedestrian Crossing ( 20 points )	Kill 20 enemies with a vehicle.
People Skills ( 50 points )	Complete the game in Co-op on any difficulty.
Party Animal ( 15 points )	Host 25 Ranked Multiplayer Matches.
Peacemaker ( 75 points )	Complete the Game on Hardcore.
Pyro ( 20 points )	Kill 20 enemies with explosive damage.
Quick Draw ( 15 points )	Kill 10 enemies using only the Autorevolver in a ranked Multiplayer Match.
Revenant ( 130 points )	Complete the Game on Insane.
Skeet Shooter ( 10 points )	Shoot 25 Trip Mines out of the air.
Sniper ( 20 points )	Get 20 Headshots.
Sure Shot ( 10 points )	Get 10 Kills in a Ranked Multiplayer Match.
Sticky Fingers ( 10 points )	Capture 3 flags in a Ranked Multiplayer Match.
Thief In The Night ( 20 points )	Capture a flag in 10 straight Ranked Multiplayer Matches.
Top Of The World ( 20 points )	Win 5 straight Ranked King of the Hill Matches.
Trooper ( 35 points )	Complete the Game on Casual.
Wall Jumper ( 20 points )	Successfully wall-jump 100 times.
Where'd They Come From? ( 20 points )	Kill 20 enemies without alerting them.
Winner's Circle ( 20 points )	Win 25 Ranked Multiplayer Matches.