half cover for some highground scenarios sounds good but backstab is just stupid.
in turn based combat it looks ok but it really doesn't make any sense.
there is already a "backstab" mechanic in 5e it's called sneak attack, rogues have it and it makes sense.
You do know that hitting from behind is a variant rule in 5e right? So no Sneak Attack isn't the "back stab" mechanic. They are litterally using a variant rule in DnD. Sneak Attack doesn't even need to be from behind to go off in 5e, you just need to be sneaky when you are attacking.
I personally don't mind the current Advantage system Larian went with. To be honest cover and advantage is some of those systems most tables have some form of house rule on anyways. At my table we use "Help action is a reaction" so people can give advantage once per round if they are within melee range. (they are distracting the enemy while their ally hits).
We used to use flanking, but that just lead to "Conga Line of Death" scenarios where you had enemy-ally-enemy-ally-enemy lines so everyone got advantag.
Height is actually a form of cover anyways. Being on high ground is benificial irl because you gain cover from it, and same with low ground.
The reason I like the rules as is: It makes the battlefield positioning matter, and thus makes combat more engaging, and tactical.
