We cannot consider any betting without money as gambling. There are some situations where money is not exchanged but is treated as a bet. I have some friends who sometimes bet with some others friends where they don't prioritize money. But if they lose the bet they are obliged to give treats. Can i consider such bets as gambling? Definitely not, Because there is no direct relation to money. Moreover, no one has any regrets even if they lose.
Staking down your money is what makes it to be called gambling and also gives you the right to have the opportunity to claiming your money if you win since you've taken the risk of loosing the money through gambling by staking it, without money being involved people will not regards it as gambling than child's play because they believe you're still not giving or making a ground on what you're playing without betting it.