Power Rangers Geo Force (often abbreviated as PRGF, and often simply called Geo Force) is fanfiction series of Power Rangers created by Runwaygirl20. The series took place in 1999, and is based on the Super Sentai series Chouriki Sentai Ohranger. Geo Force introduced all-new Ranger costumes for the first time, a pattern that would repeat each subsequent season, in keeping with the Super Sentai source material.