To play devil's advocate

Always start with a disclaimer. Say, "Just to play devil's advocate..." before your point. This tells people you aren't attacking them personally. Use it to introduce a 'what if' scenario. It works best when everyone is agreeing too quickly. It keeps the conversation alive and intellectually spicy.

Use it during a business meeting to vet a new strategy. Use it with friends when choosing a vacation spot. It is great for academic settings or debates. If your partner wants to buy a boat, use it to mention the maintenance costs. It shows you are thinking deeply about the topic.

Avoid this during highly emotional or personal moments. If a friend is crying about a breakup, do not play devil's advocate for their ex. That is a fast way to lose a friend. Don't use it when a quick decision is life-critical. If the building is on fire, don't argue for the benefits of staying inside.

This phrase comes from the Catholic Church. They had an official called the Advocatus Diaboli. His job was to argue against a person becoming a saint. He looked for flaws to ensure the process was honest. Today, it’s a staple of Western 'Socratic' debate styles. We value the 'clash of ideas' to find the truth.

Sometimes people just say, "Let me be the devil's advocate here." You might also hear, "For the sake of argument." In very casual settings, you could say, "Just playing the 'bad guy' for a second." All of these serve the same purpose: testing the strength of an idea.