Devil's advocate

Devil's advocate is a phrase often used in the English speaking world. It refers to when, for the sake of debate, someone presents a point of view they don't necessarily agree with, to make someone else consider an opposing point of view to their own. Colloquially, it may refer to saying something you don't believe to "mess with someone", for the sake of it or playful demeanour. An example of this would be if you were an atheist debating a fellow atheist, and you decided to present a theistic counter-argument, in order to help strengthen your fellow atheist's arguments. Another example would be on a mostly pro-choice forum, pretending to be anti-abortion to try and see how their arguments measure up. This is similar to real-life trolling, but not exactly the same: the person utilizing the devil's advocate is arguing in good faith and usually admits afterwards or in the middle of discussion (or possibly even before they begin) that they are just playing and is trying to put across an opposing view, and a troll is simply being an asshole who simply wants to be malicious, without revealing their true viewpoints, because a debate isn't their motivation.

The term originally referred to the Roman Catholic cardinal charged with arguing against a potential saint's canonization, before the role was greatly reduced by Pope John Paul II, though the Church does still often seek out opposing counsel during the canonization process.