A game action is simple to understand, program and implement. The more complicated part is getting your head around the idea that games work best with extendable actions. Extensibility means that the action itself may be simple, but there is scope to expand or embellish it to have many uses.
Not all actions are equally extendable, which makes finding the right ones challenging. However finding great extensions is the best way to achieve elegance in your game design. And that, in turn, leads to success.