You press the button. Nothing happens. Then your character teleports. You are dead. That is lag. It is a delay in network connection. The game is not responding in real time. The data is slow. The screen stutters. The player suffers. Lag is the enemy of every online gamer.

Lag comes from many sources. A slow internet connection. A distant server. A crowded network. A weak router. It can be temporary or permanent. It can affect one player or everyone. It is measured in ping, the milliseconds it takes for data to travel. Low ping is good. High ping is bad. Lag is the result.

Related terms

• Ping: the delay in milliseconds.
• Rubberbanding: character snaps back to a previous position.
• Desync: the game state differs between players.
• Lag spike: a sudden, temporary increase in delay.

Lag is frustrating. It is also democratic. It affects everyone. A pro player with a bad connection is as helpless as a beginner. The best games have lag compensation. They predict where you are. But prediction is not perfect. Sometimes you die behind a wall. Sometimes you miss a shot. Lag is the ghost in the machine. It is always there.