The lockstep protocol is a partial solution to the look-ahead cheating problem in peer-to-peer architecture multiplayer games, in which a cheating client delays their own actions to await the messages of other players.
[1] A client can do so by acting as if they're suffering from high latency; the outgoing packet is forged by attaching a time stamp that is prior to the actual moment the packet is sent.
This can be acquired by placing a limit on the time in which a player can announce their action.
To overcome the obvious drawback of the simple lockstep protocol, an asynchronous variant of the protocol exists wherein players advance in time free of any negotiations with other players until interaction between players exists, known as a "lockstep mode."
Such an interaction can only occur when, for example, the areas of influence surrounding two players intersect.