Clash refers to the direct engagement between opposing arguments in a debate. When one team attacks a specific claim and the other team defends it, that is clash. A round with strong clash feels like a real argument - two sides actually responding to each other rather than reading prepared scripts past each other.
Why Judges Reward Clash
Judges prefer clash because it helps them decide the round. When both sides engage on the same issue, the judge can see which argument is stronger. When both sides ignore each other and just repeat their own points, the judge is left having to pick a winner with no real comparison. Experienced judges will even lower speaker scores for teams that refuse to engage.
How to Create Clash
The simplest way to create clash is to rebut specific claims from the other side by name. Instead of saying 'the other side is wrong,' say 'their second argument claimed that X, but X fails because of Y.' That level of specificity forces the opposing team to defend the exact claim you attacked, which is clash.