This is a very freeform and streamlined RPG ruleset, inspired by the Free Kriegsspiel Revolution and Old School Renaissance movements, based on the most famous old school sci-fi RPG, but intended to be used in any setting or genre. The system is designed to be very flexible and hackable. Hacks are indeed encouraged and welcomed. 

This version of GIST! tries to be adherent to the general principle of Free Kriegsspiel Revolution: play worlds, not rules. So it is by design even more minimal and free-form than the core edition.