Game
Action is everything: the action the player takes, the resulting action that the game system or an opposing player takes, the resulting subsequent actions the players take, etc. Game mechanics are the actions that a player can take in a game.
(Slay the Dragon: Writing Great Video Games by Robert Denton Bryant & Keith Giglio, 2015. Page 44)
Game Design: The Lens of Action
To use this lens, think about what your players can do and what they can't, and why.
- What are the operative actions in my game?
- What are the resultant actions?
- What resultant actions would I like to see? How can I change my game in order to make those possible?
- Am I happy with the ratio of resultant to operational actions?
- What actions do players wish they could do in my game that they cannot? Can I somehow enable these, either as operational or resultant actions?
A game without actions is a sentence without verbs - nothing happens. Deciding the actions in your game will be the most fundamental decision you can make as a game designer. Tiny changes to actions will have tremendous ripple effects, contributing to a game with marvelous emergent gameplay or making a game that is predictable and tedious. Choose your actions carefully, and learn to listen to your game and your players to learn what is made possible by your choices.
(The Art of Game Design: A Book of Lenses by Jesse Schell, Carnegie Mellon University, 2008. Page 144)
Game Mechanic - Actions
Actions are the "verbs" of game mechanics. There are two ways to answer the question, "What can the players do?" The two kinds of actions are operative actions and resultant actions.
(The Art of Game Design: A Book of Lenses by Jesse Schell, Carnegie Mellon University, 2008. Page 140)
Dungeons & Dragons
Combat is played in round. Each round represents 6 seconds in the game world. Combat starts with initiative checks to determine the order of play for the entire battle. There are three types of actions: standard actions, move actions, and full-round actions. In a round, you can do one of four things: take a standard action and then a move action, take a move action then a standard action, take two move actions, or perform a full-round action.
(Player's Handbook: Core Rulebook I v.3.5, pg. 5)
Guild Wars
In Guild Wars, an action is considered any attack or use of a skill. The only skills that can affect any action are also interrupts.