A "friendly wager" is a bet or a friendly bet made between friends or acquaintances. It implies a playful agreement to bet or gamble on something, usually for fun or entertainment rather than for serious stakes or high sums of money. Full definition
To add even more fun, challenge and invite your friends / rivals at another clinic, pet supply store, or other neighbouring business, to participate in Tails of Help Month with a little head - to - head competition, and make some kind of friendly wager between groups - losing team buys doughnuts for the winners or hosts them at a barbecue or washes their cars or whatever you think would be fun. (tailsofhelp.com)
Also being in Vegas we as spectators can make our own friendly wagers between each other about how well the team will do or how long the team will last there. (slickstermagazine.com)
He offered a «friendly wager» to Dallas Bishop Kevin Farrell, himself an avid Mavericks fan. (religion.blogs.cnn.com)