A permutation, usually shortened to perm, is an argument that combines the Proposition's plan with the Opposition's counterplan to show that the two are not mutually exclusive. The Proposition uses a permutation to argue: 'We could do both our plan and their counterplan - there is no reason to choose one over the other, so vote for our plan because it adds value.'
Where Perms Are Used
Permutations are most common in Cross-Examination (Policy) debate, where counterplans are a standard Opposition strategy. Parliamentary formats do not always use the term 'permutation,' but the same strategic move exists: 'Judge, both policies can happen together, so rejecting ours is pointless.'
How the Opposition Responds
The Opposition responds to a permutation by explaining why the two plans cannot coexist - usually by showing they compete for resources, contradict each other's assumptions, or produce incompatible outcomes. If the Opposition wins this 'competition' debate, the permutation fails and the round returns to a straight comparison of the two plans.