by wtcannonjr
I explain it as 3 types of ACTIONS - Full, Quick and Quickcast.Choice of ACTION depends on the phase of the Action Stage, what creature is acting and what ACTIONS have already been taken by the acting creature.
Each ACTION type has a choice of ACTIONS that can be selected. See the back page of the Rulebook for a good summary. e.g. This is where moving, guarding and casting are explained.
Finally, when choosing Cast Spell as an ACTION choice the ACTION ICON on the Spell must fit with the ACTION type. i.e. some spells take longer to cast and therefore reduce the number of ACTION choices available to a creature.
I may also bring in the notion of DURATION of ACTION to reflect the different choice of ACTIONS available in each type. So a Full ACTION gives you more choices than a Quick ACTION, than a Quickcast ACTION.
Note - casting by a SpawnPoint is explained separately since it is not a creature and doesn't happen in the Action Stage.