Diego is where the New System, also known as the mind-rain, first took hold. Diego took in the new Smokies, who distributed the lesion-removing pills. Very few Diegoans have the lesions, as teachers, wardens, and Rangers are lesion-free, as are many other people. There are very few regulations regarding surge types. People can have skin ranging from snow white to coal black, snakes for pinkie fingers, and video screens for fingernails. They have no kind of Special Circumstances, so the wardens keep the peace.
There are several parks in Diego, a rock climbing area, and a Town Hall. They have no military, which lead them to almost be destroyed when Tally's city attacked.
Most of the Cutters decided to stay in Diego after the Diego War.