Skepticism triggers prove that one debater's framework is necessary to avoid moral skepticism. More formally, a skepticism trigger ran by Debater would argue that 's framework is uniquely necessary to resolve moral skepticism, and if 's framework were proven false, then moral skepticism must be true.
Skepticism triggers can be strategic because they provide debaters with a backup route in the event that they lose their framework. If a debater running a skepticism trigger loses or concedes that their framework is false, instead of losing the substantive debate, the debater can now win on moral skepticism. Of course, that debater must be winning that the skepticism trigger itself is true and that permissibility flows to their side, but many skepticism triggers are not immediately obvious that they are actually skepticism triggers until they are extended in the second speech.
How do they work?
First, it is important to understand what it means to resolve skepticism. In a world without any frameworks, moral skepticism would be true because there would be no way of deeming an action obligatory or prohibited. Therefore, a framework is needed show that we do, in fact, have moral obligations. When a framework is able to prescribe obligations and prohibitions upon its agents, it is said to resolve skepticism.
However, even if both debaters read frameworks in the round, if both of the frameworks are proven false, we are just back to where we started, and moral skepticism would be true because neither framework is able to resolve it. This is what a skepticism trigger aims to do: it attempts to prove that both frameworks in the round are false so that moral skepticism becomes relevant.
Skepticism triggers operate by proving how any framework that resolves moral skepticism must have property. Naturally, the framework of the debater reading the skepticism trigger will have property, while their opponent's framework will not.
To trigger skepticism, the debater will concede that their own framework fails. Therefore, the only viable framework left would be their opponent's framework. But, the opponent's framework fails to have property, so it must also fail! That means there are no viable frameworks left in the round, so moral skepticism becomes relevant.
could refer to any property of a moral framework. For instance, might say that frameworks need to be binding, or that frameworks need to be consistent with some meta-ethic, or that frameworks need to be able to resolve some philosophical dilemma.
The entire NC is one large skepticism trigger. Since the meta-ethic is perspectivism, truth is not absolute but is created by individuals. The NC argues that the state is necessary to provide a unified conception of truth. So, if we do not listen to the state, there would be no unified conception of truth, so moral skepticism would be triggered because moral frameworks cannot operate absent truth.