system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How can gambling be illegal in US States that run a lottery? Isn't the lotto just state-run gambling?
gpt
Perhaps unsurprisingly, when you are the body that makes the rules, you can make exceptions for yourself in those rules. Lotteries were made illegal for a time and there is no national level lottery. However, many jurisdictions have made government lotteries legal again. 

There's no requirement for the government to write an "all or nothing" gambling bill.