If a magic item or circumstance provides an advantage to a character, any subtraction results on the Fudge die are treated as addition.
For disadvantage, multiplication results are treated as subtraction.
For magic items or traits that leave the results to the fickleness of Fate, addition results are treated as multiplication.
After each session, the referee awards up to 3 xp based on criteria agreed upon before play. If I flesh out this idea more, there will be suggested criteria depending on what all the players and referee consider fun for them.
After XP is awarded, a player may spend 2 XP to buy a trait, 3 XP to increase their luck, or 4XP to increase their skill.
Traits cannot be increased above +1. A character has a limit of nine positive traits at any time. A player exchange one positive trait for a new one at any time, but this is required if a character already has nine positive traits.
In play, a character may acquire a negative trait due to a curse or other circumstance. It costs 1 XP to eliminate it, however, a character must always have at least one negative trait.
Increasing skill or luck advances the die up a step d4 > d6 > d8 > d10 > d12. The limit for a luck die is d10, a skill die is capped at d12. With powerful artifacts, other dice can be used above, below, or between the thresholds stated here.
Players are encouraged to provide a brief story about why a trait was gained, exchanged, or added. The same is true for an increase in skill or luck. It is assumed that these stories take place between game sessions. These are entirely optional.
A target number of 12 is roughly equivalent to the top 5% of human achievement. A target number of 0 is considered easy while a target number of 24 is superhuman.