Is truth or dare haram?

It depends on how it's played. The game itself isn't haram, but it often turns haram: truths that expose private sins or gossip about others, lies to dodge questions, and dares that involve kissing, touching, danger or humiliation. A clean version with friends can be harmless fun.

Games are allowed in principle

Islam doesn't ban fun. Laughing with friends, playing games and joking are part of normal life, as long as they stay clear of what's forbidden. See Is it haram to tell jokes? The problem with truth or dare isn't the name; it's what usually happens during it.

The "truth" part: what goes wrong

Exposing your own sins. Questions like "What's the worst thing you've ever done?" push people to reveal sins Allah has covered. The Prophet ﷺ said all of his ummah will be forgiven except those who openly expose their own sins (Sahih al-Bukhari 6069).
Talking about others. "Who do you secretly dislike?" or "What do you know about…?" quickly becomes backbiting or spreading secrets.
Lying to escape. Making up an answer is still lying. The Prophet ﷺ taught that truthfulness leads to goodness and lying leads to wrongdoing (Sahih al-Bukhari 6094).

You're always allowed to say "Pass" or "I'd rather not answer." Keeping your private life private is not lying.

The "dare" part: what goes wrong

Dares to kiss someone, sit on a lap, send a flirty message, drink alcohol or do something dangerous are clearly off-limits. So are dares meant to embarrass someone. Allah says:

يَـٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوا۟ لَا يَسْخَرْ قَوْمٌ مِّن قَوْمٍ عَسَىٰٓ أَن يَكُونُوا۟ خَيْرًا مِّنْهُمْ "O you who have believed, let not a people ridicule [another] people; perhaps they may be better than them." Quran 49:11

Silly, safe dares are a different story: doing an impression, singing a nasheed badly, or eating a spoonful of mustard.

How to handle it with friends

If the game starts at a party or sleepover, you can suggest house rules: no questions about other people, no physical dares, and anyone can pass. If it's already heading somewhere uncomfortable, step out with a smile: "I'm out for this round, I'll get the snacks." The Prophet ﷺ said, "Whoever believes in Allah and the Last Day should say what is good or keep silent" (Sahih al-Bukhari 6018). For more on social nights, see Can I go to college parties if I don't drink?

Better alternatives

Would-you-rather questions, quizzes, charades, Pictionary or board games give the same laughs without the risk. See Can I still play video games as a Muslim? for more on games in general.

Key points

Truth or dare isn't haram by name; the content decides.
Avoid truths that expose sins, gossip about others or force lies.
Avoid dares involving physical contact, alcohol, danger or mockery.
You can always pass, set clean rules, or suggest another game.

Tip: Have a go-to alternative ready, like "Let's do would-you-rather instead." Offering a fun swap works much better than just refusing.