The Israeli army's death toll in Gaza is already almost twice as high as during a ground offensive in 2014, a reflection of how far it has pushed into the enclave and of Hamas' effective use of guerrilla tactics and an expanded arsenal.
Israeli military experts, an Israeli commander and a Hamas source described how the Palestinian group has used a big weapons stockpile, its knowledge of the terrain and a vast tunnel network to turn Gaza's streets into a deadly maze.
At their disposal they have arms ranging from drones rigged with grenades to anti-tank weapons with powerful twin charges.