I think a lender should have a binding agreement that the borrowers have to sign before they can be granted the loan, so that no matter how the borrower tries to outsmart the lender so that they won't have to repay the loan, the agreement will be presented as evidence before every legal panel. If one lends money to friends and the lender is expected to get the loan repaid, I think they should present strict rules to the borrowers because there are some people who love being debtors. Even if they have the money, such people don't like to pay back their loans. But if the borrower is lending to a best friend or relative and doesn't care if they get repaid or not, then the borrower can just give the loan with strict rules.
The problem is that in some countries like mine it's forbidden to lend money, as you can be considered a loan shark by the local justice system. Therefore, a document signed by lender and borrower will just corroborate in favour of the borrower in debt, as he can blackmail the lender. And there is nothing the lender can do, because if he goes to the court, he is the one going to be punished by the crime of lending money.
If someone asks money, especially for betting purposes, the best answer you can give is to tell them to seek for a lending platform or bank, instead of asking you for funds. It's just too complicated to deal with loans without guarantees ensured by the law of your country. Unfortunatelly the truth is that the law protects the monopoly of banks on this matter, so they don't have competition on this business, where common citizens could be offering loans with cheaper interest rates in an open market.