On Constructions:

• {A} represents the action of assigning a worker to a construction. This can be done only at sorcery speed.
• The number in the bottom right corner, on Multiverse, represents the total number of workspaces a construction has. Greenhouse can have two workers assigned to it per turn. I imagine that on real cards, this would be instead represented by two large round circles with the worker symbol in the middle.
• You can assign workers to any constructions controlled by players on your team.
• Workers are not permanents, counters, or tokens. They reside in the command zone unless assigned.
• Constructions with Staff always have the staff number tied to the number of workspaces they possess.
• Workers return to your command zone as you untap permanents in your untap step.

Constructions without Staff: University

Following Jack's comment on Grocery Store, here are some revisions to consider for Constructions:

• Workers (And, by extension, Staff) do not exist as a new game object. Instead, creatures are assigned to constructions, and creatures currently assigned to constructions are known as workers.
• Creatures can only be assigned to a construction if they don't have "summoning sickness" and are untapped.
• A creature assigned to a construction can't attack or block, and its activated abilities can't be activated. A creature that has attacked, blocked, or activated an ability this turn can't be assigned to a construction.
• Creatures become unassigned and cease being workers as you untap permanents.

Now that workers are just creatures, wouldn't it make more sense to take advantage of what creatures already do to show they've been used, i.e. you tap a creature to assign it to a construction until it becomes untapped? It's not quite the same, but it's way more Magic-al.

Good idea with assigning creatures, but doesn't this make construction basically like vehicles? Except for power 2 you need 2 creatures, but apart from that it looks the same. Would love to have non-vehicle constructs in magic though, and I think it could work on a lot of planes. Non-mobile cannons for example would work better as constructs than vehicles flavourwise, cause you need somebody to operate them but that doesn't make them a vehicle per se.

Eh, it feels pretty different to me. With constructions, it only ever takes one creature to activate, but you can activate multiple times for additional benefit. Plus the fact that constructions aren't creatures is completely different.

It's more like an activated ability just saying "Tap an untapped creature you control:" like Glare of Subdual.

This card is actually far more problematic under these new rules: it goes exponential. This turn I make 2 plants, next turn I make 4 plants, turn after I make 8 plants...

Obviously some of the designs would have to be revised, but Alex, you can only ever assign two workers to this, since it has two action spaces. It's two creatures a turn (which even under the current rules is probably too good), but it's not exponential.

dude1818: Tapping the creatures to assign them as workers makes a lot more sense that restricting them in very similar ways without actually tapping them.

With creatures are you assuming it still makes N workers ETB? I guess not?

I'm not sure how it should be balanced. Using creatures means you don't have constructions with insufficient workers. But is a significant cost needing to park your creatures in order to use it.

No, staff would no longer exist, and workers would no longer be created upon ETB.

It would probably need an errata that says "use this ability only once each turn" to make it work like a magic card. Putting something like that into the comprehensive rules is also a possibility, but not necessary.

If staff no longer exist, you may rewrite the whole mechanic like this

Greenhouse Construction Tap two untapped creatures you control: Put a 0/1 green Plant creature token onto the battlefield. Use this ability only once each turn.

That's... It completely removes the point of having Construction be its own card type. You've just redesigned enchantments with activated abilities.

When I say staff would no longer exist, I mean literally this triggered ability that the cards have to provide themselves with workers under the initially proposed rules. Action spaces and the construction card type are separate from that. In the revised rules proposition, creatures would instead fill action spaces. It would be an action vaguely akin to attacking, since it would require tapping and could only be performed if the creature didn't have summoning sickness.

What exactly is the point of Constructions being it's own card type? Is it supposed to be a card for a new card game or should it work in MTG? Because then it wouldn't make too much sense to put all the rules regarding them into the comprehensive rule book if they would work like Glare of Subdual anyway.

Current thoughts on Action Spaces:

• Creatures are assigned to Action Spaces. (There are no workers.)
• This happens during the Declare Attackers step, as an alternative to attacking.
• As you declare attackers, you assign creatures to attack players and planeswalkers, and assign creatures to action spaces. Like attacking, creatures tap as they are assigned to an action space.