Action

An action is a trigger in a MUD or MUCK that causes an event to happen in the system which may or may not generate output to the user. Actions are attached to objects, and are typically invoked via a text interface in the format:

action object

In the case of "drop ball", the ball object would execute it's drop action. The drop action could simply return text to the user, such as "You dropped the ball", could use MPI to generate a dynamic response, such as "Hey, Sean, you dropped the ball", or it could execute a program, such as disconnecting the user from the system.

Certain actions are called global actions, and these actions are available for players to execute regardless of their location or what objects they possess. A teleport command would likely be a global action, unless one could only teleport when holding a certain ring, in which case that ring would have the teleport action associated with it.

All MUDs, MUCKs, and MOOs are based on action-driven paradigms.