Professor Portal
After completing co-op, complete Calibration Course online with a friend who hasn’t played before
6/8/2012
3:59:34 AM
Ultra Rare 1.7%
Asking for Trouble
Taunt GLaDOS in front of a camera in each of the five co-op courses
6/8/2012
1:32:18 AM
Very Rare 6.0%
Put the Posse on a Pedestal
Attain over 50,000 posse points in a single Free Roam session
6/7/2012
10:10:27 AM
Ultra Rare 1.3%
Still Alive
Complete Course 4 with neither you nor your co-op partner dying
6/1/2012
5:37:32 AM
Ultra Rare 1.4%
Obstacle Building
Complete all test chambers in the Excursion Funnels co-op course
6/1/2012
3:08:57 AM
Rare 15.7%
Triple Crown
Solve 3 co-op chambers in the Mass and Velocity course in under 60 seconds each
5/31/2012
4:08:01 AM
Ultra Rare 1.8%
Portal Conservation Society
Complete Chamber 3 in the Hard-Light Surfaces co-op course using only 5 total portal placements
5/31/2012
3:47:38 AM
Ultra Rare 2.1%
Bridge Building
Complete all test chambers in the Hard-Light Surfaces co-op course
5/31/2012
3:20:12 AM
Rare 20.6%
Can't Touch This
Dance in front of a turret blocked by a hard light bridge in co-op
5/31/2012
2:32:11 AM
Very Rare 7.9%
The Quick and Everyone Else...
Be the top scoring player in any three consecutive FFA games in public matches.
5/28/2012
5:06:28 PM
Ultra Rare 0.9%
Go Team!
Be on the winning team for four consecutive victories in any team based game in public matches.
5/28/2012
4:08:39 PM
Ultra Rare 1.7%
Call it a Comeback!
Come back from a 2-0 deficit and win a Hold Your Own game.
5/27/2012
3:32:00 PM
Ultra Rare 0.3%
We Must Protect This House!
While on defense, do not allow the attacking team to capture any of their objectives
5/27/2012
3:05:45 PM
Ultra Rare 0.8%
Triple Crown
Get first place in all races in a Grand Prix in the Races playlist
5/27/2012
2:59:48 PM
Ultra Rare 0.3%
From Glue to Mon Dieu!
Get last place in a race, and then first in the next race in a Grand Prix in the Races playlist
5/27/2012
2:30:07 PM
Ultra Rare 0.6%
One Die to Rule Them All
In a Multiplayer Liar's Dice game, win with only one die left
5/27/2012
2:08:38 PM
Ultra Rare 0.5%
Good Call
In a single Multiplayer Liar's Dice game, successfully make a spot-on call
5/27/2012
1:53:38 PM
Ultra Rare 1.0%
In A Van Down By The River
In a Multiplayer Poker game, win a hand on the last card when you were losing prior
5/27/2012
1:40:47 PM
Ultra Rare 1.0%
Headhunter
Kill 5 players via headshot in a single Shootout or Gang Shootout.
5/26/2012
6:27:18 PM
Ultra Rare 1.5%
Stick and Move
Get 3 kills with knives or throwing knives in a single competitive match.
5/26/2012
5:51:22 PM
Ultra Rare 0.4%
Who needs Deadeye?
Kill 3 or more players in a standoff or showdown.
5/26/2012
5:41:57 PM
Ultra Rare 0.9%