Why Do Random Sims Show Up and Start Fights in The Sims 2?

This is a known "random townie" bug in The Sims 2. Several factors can trigger aggressive visitors:

Common Causes

• Bad relationships: Past negative interactions or rumors make townies hostile.
• Jealousy: Townies attracted to your partnered Sim may provoke conflict.
• Trait-driven: "Mean," "Evil," "Jealous," or "Kleptomaniac" traits increase aggression.
• Lot trait "Lot of Trouble": Increases random negative events.
• NPC glitches: AI sometimes acts out of character.
• Custom content conflicts: Mods/CC can cause behavioral bugs.

Fixes to Try

• Check Relationships panel → improve bad standings via positive interactions.
• Move lots or change lot trait.
• Avoid trouble-causing traits when creating Sims.
• Update to latest patch; remove custom content.
• Use ResetSim [FirstName] [LastName] cheat on the aggressive townie.
• Don't ignore them—gift/compliment to de-escalate.

Can't eliminate townie chaos entirely, but these steps significantly reduce it.