You need a least 2 people that know the game.
It starts with someone that knows the game and says Û÷I’m going to have a party, do you wanna come? Well, you can only come if you bring me a presentÛ_’
The other person that knows the game will say Û÷Can I come to your party if I bring aÛ_.’ There must be something that links all the things, whether it is the number of letters in the word, or that it begins with the same letter each time, or any other link you make up.
The game continues until everyone has discovered the link.