The Joker does have scars in many comic storylines. These scars can vary in appearance and origin depending on the specific comic. Sometimes they're part of his origin story, adding to his sinister and unpredictable nature.
The Joker's scars story is not based on a true story. It's a product of the creative minds behind the Batman franchise. They use these fictional elements to explore themes like madness, chaos, and the nature of evil. The scars are just one aspect of the Joker's overall complex and disturbing persona.
In the movie, the Joker has different origin stories for his scars. One version is that his father gave him those scars when he was a child. It's a very dark and tragic backstory that contributes to his descent into madness.
There was this time when the Joker was messing around with his acid - you know how he loves his chaos. He accidentally spilled some on his hand. Instead of being angry, he laughed it off and now has a scar there that he likes to show off as his 'acidic mark of fun'. He'll tell people that it's a reminder of the time he had a 'close encounter with his favorite toy'.
In some comic versions, the Joker's scars origin is a mystery or has multiple conflicting explanations. But in one common story, he claims they were from a traumatic event in his past.