What are the Straw Man, Ad Hominem, and Red Herring fallacies?

Three classic informal fallacies of irrelevance: attack a distorted version of the argument, attack the person, or change the subject.

• Straw Man (Strohmann) — you misrepresent your opponent's position as a weaker, distorted "straw" version, refute that, and claim victory over the real argument. The fix is the principle of charity: rebut the strongest reading, not the flimsiest.
• Ad Hominem ("to the person") — you attack the arguer (their character, motives, circumstances) instead of their argument. The argument's merit doesn't depend on who makes it; a flawed person can still state a true premise.
• Red Herring — you introduce an irrelevant but distracting point to drag the discussion off course, so the original claim is never actually addressed.

All three are fallacies of relevance: none engages the actual claim on its merits. Straw Man distorts it, Ad Hominem dodges it by going after the speaker, and Red Herring abandons it for something else.

Tip: Ask "is this aimed at the argument itself?" Straw Man hits a fake version, Ad Hominem hits the person, Red Herring hits a different topic — all three miss the real target.