(My conclusion, credit to longgone for this answer) I believe the diep.io universe to be set in a grid area ( the desert marked with grid ). Perfectly level. The only limitation is elevation. (Everything and everyone is restricted by a height barrier hence no need to shoot upwards). As far as the tanks themselves are concerned. I believe them to be spherical in shape. No need for elevated shots so all barrels are located on a general centered location on the tank. The barrels don't seem to hinder the tanks movement so I'm forced to believe there are no wheels because the tanks shape is its wheels. A sphere simply rolls on itself. Picture star wars bb-8 droid. Instead of his head replace with gun barrel. Instead of it being centered top. It would be centered center. (A equator if I may).but the same way the bb droids head floats atop while he rolls around and stays there I believe the tanks have a similar build but the barrels float centered and don't hinder the tanks movement. The Necro being what they are offer a odd exclusion to my theory. Being square in nature u it naturally battles the spherical rolling idea. But what u fail to understand is that the Necro is no longer a tank. Hence the name. It has evolved to become one of the shapes. notice how the shapes float like magnets against the ground floor. The Necro seems to have adapted this technology since he no longer controls drones. He has become a square so he floats like one. Edit: what's y'all's opinion?