A turn is a rebuttal move where a debater takes an argument from the opposing team and uses it to support their own side. Rather than attacking the argument directly, a turn accepts the claim and redirects it. When it works, a turn is one of the most damaging moves in debate because it simultaneously defeats the other side and strengthens your own.
Link Turn vs Impact Turn
A link turn argues that the opposing team's policy actually leads to the opposite outcome of what they claim. An impact turn argues that the outcome they claim is good is actually bad (or vice versa). Both types force the opposing team to defend their own argument from a new angle.
Example of a Turn
Opposition: 'Raising the minimum wage will reduce employment.' Proposition link turn: 'Actually, raising the minimum wage increases consumer spending power, which drives up demand for local goods and services, which creates more employment, not less.' The claim is accepted (minimum wage affects employment), but the direction is reversed.