There will be a few pre-made contracts available so that you can try out some of the stuff in the game before you have unlocked them or if you just don't feel like starting off with building your own contract. The intention is to cycle what these contracts include every now and then.
The number of slots for items in the contracts will be fixed. It's currently 1 commander, 3 commander gears (weapon, armor and equipment), 3 specs (overall changes to your force) and 6 boxes (utility abilities, such as rocket strikes and turrets and units with up to two different upgrades each, such as better armor or an attached flamethrower etc).
You spawn your units from your commander (who has the combined role of a hero and a mobile headquarters). You can only spawn the units made available to you through your contract (the contracts replaces the concept of base building in traditional RTS - instead of building a building that grants you a new unit or tech, you just choose to have it in your contract instead). Only when your commander unit is eliminated (and thus all your droids) are you able to change your contract. So when you choose your contract, you don't need to know what you have already spawned - because you have nothing
So what determines what you are able to spawn? Is that in you contract screen somewhere? In other words you can only spawn certain creatures (units) that you have predetermined from the contract screen. Is that correct? Because I'm not seeing where that might be.
"Boxes" are flashy gateway devices that spawn stuff into combat - they contain either units or more powerful abilities. So in the contract image you've found somewhere and posted above, you'd be able to spawn the units Skitters, Sentries, the Piledriver, Phalanxes and a Razor. The Rocket Strike is an artillery ability.
So a player must be completely eliminated first before they can adjust their base strategy by changing contracts? Do you think there will be enough time for them to catch up... in other RTSes if you see that your opponent has units that can't be countered by your current build, you can quickly change your unit make up to respond.
I guess 'upkeep' will keep victory in the reach of someone who lost an earlier round.
Yes. When you are eliminated you have the option to switch contract if you want to have another loadout to counter your opponent's builds. Some player might want to have highly specialised counter-built contracts in which case the player will have to be eliminated before being able to properly counter the enemy. However, building versatile contracts is a highly viable option too, allowing you to switch which units you have spawned by recalling your current units and spawning new ones that are up the to current task you're up against. It all comes down to how you chose to balance your builds
The upkeep is a pretty low cap compared to many other RTS games. You will probably maximize you upkeep in 30 seconds or so. So that when you are eliminated, you are quickly ready to enter combat at full fighting strength again! You usually reach your cap after spawning 2-4 units (depending on their upkeep cost). Since you have 6 slots for units available in your contract, this allows you some room to switch which units you have spawned at the same time depending on what you are currently fighting or aiming to do.