Portal Conservation Society
Very rare2.3%ObjectiveOptionalMulti-player
Co-operative
Complete Chamber 3 in the Hard-Light Surfaces co-op course using only 5 total portal placements
Complete Chamber 3 of the Hard-Light Surfaces course using only 5 total portal placements between the two of you. That's five portal shots for the whole chamber, combined - so work the solution out first and agree exactly who places which portal before anyone starts firing. Reset the chamber if you overshoot the count. The most planning-heavy of the co-op challenges.