Party is the fourth game mode in Agar.io. In order to play this mode you'll have to create a party. The game will generate a 5-character code (e.g. agar.io/#5QECV) that you can send to your friends so they can play with you. There are no rules here - you are free to team or eat viruses.
Party's original purpose was to allow a way to play with friends, and to reduce teaming in other game modes. However, some people are abusing it and using Feeder bots to gain mass.
Notes
- Party is the only mode that completely lacks the "Anti-teaming" measure. Although excessive W'ing your partner still results in mass decay, and you can easily lose many thousands of mass in a matter of minutes if you take this to the extreme.
- Party Mode was added to the mobile version in early December 2017.