The barrier (class 3) from the Stealing Creation minigame is made by using a class 3 of sacred clay on a creation kiln. It is the third weakest barrier that is used to keep members of the opposing team from accessing a resource that your team is gathering. The barrier will create a wall around the chosen resource spot with portals colour coded to the team that created it. Only members of the team which created the barrier can pass the barrier. A barrier may be destroyed by the other team attacking the barrier over time until the barrier is destroyed. A class 3 Barrier requires level 40 Construction to make from creation kilns. The barrier may only be repaired by class 3 barriers or above. The lower forms will not work. If a player happens to die they will spawn to the nearest built barrier or in the teams base.
The class 3 barrier keeps the enemy team from getting to whatever you placed it around. There are several reasons that you might wish to keep the other team out. One reason might be to protect the low level skillers from attack while the players that wish to kill take care of them. Another reason could be to keep the other team from taking your teams higher level of clay. You may also wish to build the barrier around a creation kiln so the other team may not use it.