You can compell anyone to engage in a rap battle with you

There needs to be a beat playing (can be anything from instrumental music at a party to you pulling something up on ypur phone) and you have to be the one to offer the challenge by dropping the first verse in earnest. They also obviously need to be close enough to hear you and respond.

You can hold them under this condition form for 5 minutes at a time so long as you are also genuinely trying to engage in the battle as well, after which there is an hour cooldown for that specific person.