Hiya!
I want to know what they are doing about the Exit Economy. You know, when a PC has to walk across a room (or"area"), maybe open a door, and step through. Everyone has to do this to exit one area into the other. If the room is 30', it's just one Exit Action, right? And everyone gets a free Exit Interaction so they can open the door? (Or close it). But nothing is mentioned about what it takes to walk to the door, close it AND lock it. What about if the room is cluttered? Does it take two Exit Actions? What about a chamber that doesn't' have a room? Or what about if you are in a cave system? There's no specifics about how much of a cavern area counts as an actual 'area'?
...if the above confused you, it should. As far as I know there is not such thing as an "Exit Economy". Yet. My point was that, IMHO, "No, there is no such thing as an 'Action Economy' in an RPG". This term only came into existence because someone decided to attempt to parcel out what players and GM's have been doing for decades into a 'specific action-choice-that-takes-X-amount-of-time'.
My point is that when Mike says:
"If this phrase comes up as part of the design process, we have probably done something wrong. If we're thinking of actions as an economic resource that are being spent, I think we've made the game too complicated."
...that I think he's talking about it in a "detailed mechanical choice", where every choice available to a PC needs to be given some allotment of "time". This "Action" is then divided up into smaller and smaller parts. A "Full Action" takes 6 seconds. A "Partial Action", takes 3 seconds. A "Bonus Action" takes 1.5 seconds. A "Free Action" takes 0.5 seconds. Then they list EVERYTHING in the game in terms of one of these "actions". But this is a BIG problem, again, IMHO.
The problem is that when a game has decided this, players/GMs will naturally start asking..."So, can I do TWO 'Partial Actions' then? Pulling out a Wand and using it is a Partial Action. If I already have the wand out, can I just use it twice in the Round?". Now what? Well, now the game has to make an exception or make some kind of qualifier under "Using Wands". And that's just one of an innumerable number of things that can take place in the course of of a TTRPG session. TTRPG's, by their very nature, are NOT "tactical turn based" affairs. Some aspects may
seem like it...but they aren't. They aren't because virtually ANYTHING can (and should!) affect things as play moves on.
Until someone actually coined the term "action economy", it was never a problem. What would be considered an "action economy problem" now would have just been a slight disagreement or question about some action. "Can I use two wands in one round if I have one already in each hand?"...now the GM and players think about it, decide what they want for their game, and say 'yes' or 'no' or something else 'yes, but...'. No matter what their decision is, it wouldn't be "right" or "wrong"; it would just be how they choose to run their game. But with this "action economy" now labeled and specifically defined into 'types of actions', NOW you have arguments when the rules clearly look like it would be (or wouldn't) possible to use two wands in one round...because the player/GM can both look at the "rules for Actions". Now there's a third party involved in the discussion (the Rule Book). Now the player and the GM each start searching through the books looking for other "actions" that support their standpoint on the matter. ... ... I think that was what Mike was trying to get at. If everyone at the table starts pointing to 'choices of things to do in a round' as supporting their particular desire, all that does is lead to table arguments and accusations of "My Players are Rules Lawyers!" or "My GM is a Control Freak!".
I for one am EXTREMELY HAPPY to read what Mike wrote.

Just because he isn't' focusing on "action costs", doesn't mean he's not thinking of how to word certain rules and things. It just means he's not focusing on assigning an "action cost" to every freaking thing in the book, and instead leaves any specifics of what is or isn't possible in the hands of the GM.
^_^
Paul L. Ming