I was just reminded of SLUG by Fudge creator Steffan O’Sullivan, from 1992 & 1993.
Each character is described any way the player wants. … When the GM asks a player to roll some dice, the player should roll some dice. … With the GM’s permission, … traits can be added, or existing traits or skills improved, after the gaming session.
I was quite impressed by that at the time. I was also in love with Fudge and bought my Fudge dice back then.