CONCEALMENT IS NOT COVER
For those of you not familiar with the terms, let me explain...
This is concealment::
So is this
When I am CONCEALED behind "concealment" you cannot see me; but if you shoot through my concealment where I happen to be, you WILL hit me, whether you can see me or not.
If I take COVER behind concealment, I will STILL be shot.
The interior walls and furnishings of most houses are CONCEALMENT not COVER. "The Forest" is concealment, not cover". Curtains, camouflage netting, any other thing which is soft and flexible and obscures view is CONCEALMENT, NOT COVER.
CONCEALMENT DOES NOT STOP BULLETS.
These are both soft cover:
Those are a police cruiser, and a stick built homes exterior walls respectively.
They will both conceal my position from the enemy, AND stop or substantially slow down to hopefully non-lethal velocities; low powered handgun rounds, some small caliber rifles, and some low mass secondary projectiles (shell fragments, debris from bombs etc...).
They will not stop rounds from high powered handguns or rifles, most assault rifles, light or medium machine guns, or high velocity high mass shell fragments or secondary projectiles.
Multiple hits to the same location from even light projectiles will get through.
These are all medium cover:
Medium cover will both conceal my position from the enemy, AND stop their incoming fire from hitting me, up to light machine guns, assault rifles, medium sniper rifles, most mortar and grenade fragments, and light to medium shell fragments.
However, enough concentrated fire from even light machine guns or small caliber rifles, will eventually punch through. Heavy machine guns, antimateriel rifles, RPGs, and cannon will punch through fairly easily, possibly in one or two shots.
That, is why thin stone, brick, or concrete walls are only MEDIUM and not HARD cover. Single layer sandbag walls and double layer straw bale walls are somewhere between light and medium. Double layer sandbag walls, or sandbag over straw bale, are somewhere between medium and heavy.
THIS is hard cover:
Yes, those are respectively a 2+ foot thick stone wall, and an M1 Abrams tank. Both are good "hard cover". Enough water, sand, stone, or steel, makes for good hard cover; but "enough" varies greatly.
Hard cover stops all projectiles fireable by man portable and small crew served weapons. Basically everything smaller than a 25mm cannon, or medium artillery, and you should be good.
Even then however, repeated hits to the same point can chip through.
So, in your "realistic" game, the good guy with the .50 cal sniper rifle? Yeah, he can shoot through the canvas wall of the tent and kill the bad guy. And the good guy hiding behind the turned over kitchen table? Yeah he's toast.
End of lecture...