Is it illegal to 1v1 for money?

Could you please clarify what you mean by "1v1 for money"? Are you referring to some form of gambling or betting where two individuals compete against each other for monetary gain? The legality of such activities can vary greatly depending on the specific jurisdiction and the laws that govern gambling and betting in that area. In many places, gambling is heavily regulated and requires a license or permit to operate legally. Therefore, it's important to check the laws in your specific location before engaging in any form of gambling or betting for money. Additionally, it's worth noting that even if a particular activity is not explicitly illegal, it may still be unethical or unwise to engage in it due to the potential risks and consequences.