Something we tried during the S.T.A.L.K.E.R. : Blood in the Red Forest game in Illinois was sending a team of Loners into a barn to get propane tanks to complete a mission objective, while a Controller and two Snorks were lying in wait. Once inside the Controller went active and began attacking the Loners, meanwhile the Monolithians and Zombies barricaded the Loners into one side of the door and began coming around the other side to flank.
It was a very well planned mission that succeeded in causing about 89% casualties to the Loner's team.
Another one we did was setting up a minefield with flour and CO2 airsoft mines, we sent the opposing team out to clear the minefield but when they got there we did the infamous Soviet ambush; three of our teams was on their left flank, right flank, and one facing the front of them in a fortified position while we all rained hell on them from an elevated position while they were stuck in a minefield.
No one went home after that one.
