Hall, grass, hard surface.
Children in freely spaced pairs, side by side with elbows linked. Two children stand free. One free-standing child is the tagger; the other child is the runner. Tagger chases the runner, if the runner is caught and tagged they immediately reverse roles and the runner chases the tagger. The runner can, at any time, avoid being caught or chased by joining onto a group of 2 by linking elbows with an end person. When this happens the child on the other end of the threesome is “bumped” off and is chased by the tagger.
Divide the class in half and have 2 games going at once. This can be played with 2 taggers and chasers, once the children are familiar with the game.