u/Worth-Shoulder8033

Does anyone have any insight on how to do a charity poker tournament in a bar with a cash prize to the top three winners without being illegal? I have a patron battling stage four cancer and his friends want to do this as a fundraiser. The bar is simply the location and not garnering anything from the game, only sales of food and drink of which we're donating a portion to the charity as well. The thought is to do a suggested donation for players to build the pot. Half the pot will go to the charity and half to the top three winners. There will also be vendors, bands, and auctions to help raise additional money. Has anyone done something like this in a manner that didn't run afoul of gambling laws?