Root Scourge

Surface is occupied by a mutated plant species. Humans fought it for hundreds of years and lost the fight.
With humanity's search for an answer for survival, a new way of life has began.
Under the surface, city states that are safe from the roots.

Hundreds of years passes.
Countries are no more.
History is no more.
Human domination of the nature is no more.
Human technology has changed and adapted.

There is only one way to survive: Stay underground.

But humanity still has some needs from the surface. Automated systems are limited. Someone needs to go up. Someone needs to solve the problems. 

You are one of the few professionals that can roam the surface.

You have the equipment, knowledge, experience and the right vehicle for this job:
S.A.B.R.E (Specialized Armored Breaching Recon Expeditionary)
An old model military armored recon vehicle.

After it was outdated and left the military, it spent decades under the hands of mercenaries like you.
You are the late owner of it.

S.A.B.R.E can climb steepest surfaces (as long as its tracks are not being pushed too hard)

It has a industrial shredder attached in front of it so you can gather resources with it.

Normally it is a military personel transporter, but your S.A.B.R.E is not. The seats are thrown away to create space for weapon systems. You need them to combat the roots and other dangers on the surface.

S.A.B.R.E has a modified scanning device that is perfected by its previous users. It can detect resources, points of interests and secret stashes that would normally go unnoticed.

It can synchronize with the Comm Towers (CT), so you can access the Logistics Points (LP) of that area. You can use LP to craft upgrades for S.A.B.R.E and trade materials with the connected city states.

You can modify and upgrade all of these features to your liking and needs.
Gather resources, loot important high quality parts and craft upgrades.
Better equipment means better chances of survival against the Root Scourge on surface.

But be careful.
Because some things you do can awaken the undisturbed roots.
If the roots are disturbed, they will increase the UCIM (Upper Crust Irritation Metrics) threat levels on that area.
The UCIM threat level is the indicator of how much irritated the roots are on that area.
S.A.B.R.E has devices that can detect the UCIM threat levels.
Use it to navigate safely, and know when to run away.