An Echo is an alternate reality that is nearly identical to a point in Homeline's past.

All books set in historical periods can be treated as Echo realties. Many cover huge periods of history:

Important NoteEdit

"Infinity names echoes based on the number of years the echo’s local present lags behind Homeline"[1]

For example "An echo with a local present date of 1776 would be Echo 251, or 251 Minus (both names get used interchangeably), since 1776 is 251 years behind Homeline’s present date of 2027."[2]

So something like "Echo -222" would NOT be an Echo of 222 BCE but rather an Echo of whatever is 222 years behind Homeline’s present date which likely is c 2038 (in our 2018) making it an Echo of c 1816.


  1. GURPS Infinite Worlds 85
  2. GURPS Infinite Worlds 85