PyTectonics is a 3d plate tectonics simulator written in Python to provide realistic terrain generation for hobbyist world builders. PyTectonics seeks to use simple yet scientifically defensible models to simulate plate motion. Mechanistic models are preferred where possible to reduce guesswork when choosing model parameters. Plates move correctly about their respective Euler poles, and elevation is determined mechanistically through isostacy. Island arc formation uses simple models used in literature (Ben-Avraham amp; Nur 1980), and additional literature will be incorporated to account for features including erosion (Simoes et al. 2010) and continental orogenesis detection (Cloos 1993). PyTectonics requires the vpython and scipy libraries.