The objective of Agar.io is to grow a cell by swallowing both randomly generated pellets, which slightly increase a cell’s mass, and smaller cells without being swallowed by larger cells. It can be played in a death-match (free-for-all) or between teams.The goal of the game is to obtain the largest cell; players restart when all of their cells are swallowed. Players can change their cell’s appearance with predefined words, phrases, symbols or skins. The more mass a cell has, the slower it will move.Cells gradually lose mass over time.Viruses split cells larger than them into many pieces and smaller cells can hide underneath a virus for protection against larger cells. Viruses are normally randomly generated, but players can make new viruses by feeding a virus, i.e. ejecting a small fraction of a player’s cell’s mass into the virus a few times, causing the virus to split up and hence create another virus.Players can split their cell into two, and one of the two evenly divided cells will be flung in the direction of the cursor. This can be used as a ranged attack to swallow other smaller cells, to escape an attack from another cell, or to move more quickly around the map.Split cells eventually merge back into one cell. Aside from feeding viruses, players can eject a small fraction of their mass to feed other cells, an action commonly recognized as an intention to team with another player. A player can also eject mass to trick enemies into coming closer to the player. Once an enemy cell is close enough, the player can split his/her cell to eat the baited enemy.