I can only comment on Planetside, and if I'm wrong someone correct me, it's been years since I played.
As you level up in Planetside, your character does not get more health, however, you do get more abilities, and you unlock the ability to get better weaponry/vehicles.
When you start out, you have something like 4 points. With those 4 points, you can buy equipment/vehicles which are 4 points or less. As you level up, get more points.
For example:
A tank might cost 4 points.
A reaver (flying aircraft) might cost 6 points.
If you start out, you can get the tank but not the reaver. If you choose to get nothing, you can go on foot until you gain 2 combat rank, which would give you 6 points, which you can use to get the reaver. Then when you hit combat rank 6, you now have 10 total points, in which you can then buy the tank and be able to use that or the reaver.
They had a ton of different vehicles, and different arms, so you can pick and choose what your character may have.
Granted, while you are in a tank, you have a ton of firepower and armor, as your character is inside the tank. Basically people would have to kick the crap out of the tank, and you'd have to eject when its disabled, then you run around on foot (and if you didn't have enough points, you'd be stuck with your noobie pistol, etc)... Or if you had the points, maybe you'd have the machine gun along with the tank.
To make a long story short, it's more like Battlefield games, but only those with experience/points can pick up the certain vehicles. Not everybody can jump in the jet, not everybody can jump in the tank. Only those who "trained" in those can use them.
There could be a special armor for your character that you spend points on to make yourself stronger, but if you spent the points on that, you wouldn't have as good weaponry, etc.
I quit playing when it came out the mechwarrior bots. They were just about indestructable to just about anybody on foot with any weaponry.
