>>48470
>>48472
>>48473
"Realistically" mechs could be a variation of exoskeletons. With armor, and mount points for weapons.
They don't need to be several meter tall robots. As for the dimensions could be a height of a tank (2-3 m) max, the width and length are obviously less. Not sure about the speed, or agility, or the power source... (gadget X propulsion)
They could fix machine guns, anti-material rifles, infantry anti-tank rockets, even mortars upon them. Or some kind of a multiple rocket launchers (like on the Catapult models or something).
They should withstand small arm and machine gun fire, grenade and mortar shrapnel, anti-infantry mines, but I wouldn't expect them to withstand something more serious.
Maybe they could climb stairs, or the lighter models could scale walls.
They should have some kind of HUD, with screens which could display video feed (from other mechs, or drones).
One problem I see especially with the heavier ones: the pressure from the weight is distributed on too small areas (soles). They would need wide feet.