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.
Sometimes an idea won't let go even after analysis. Here's a more streamlined novel dice mechanic.
The game has various target numbers for success based on difficulty. They start at 0 increasing in increments of 3.
When rolling for success, you have a fudge die, a skill die (d4 through d12), and a luck die (d4 through d10)
On a roll, the fudge die tells you to add, subtract, or multiply the skill die and luck die. For subtraction, it is always Skill - Luck = Result. (Yes, this allows for negative numbers).
When you generate a character, the character has a d6 and a d4 die to use. You must choose a skilled or lucky tag. A skilled character starts the game with a d6 for skill and a d4 for luck. A Lucky character starts with d4 for skill and d6 for luck.
The character also starts with three positive traits and one negative trait. Each positive trait adds one to the result of the skill die, each negative trait subtracts one from the result of the skill die.
An example character Mezteloc the Sorceror
Mezteloc chooses to be a skilled sorcerer and begins with skill die of d6 and a luck die of d4.
He chooses three traits: Conjuring +1, Metamorphisis +1, and Survival +1. The negative trait is Melee -1.
As a skilled sorcerer, Mezteloc often finds himself searching for mystic items and esoteric materials to grow in power. Being able to forage for a bit of food during his excursions helps him to rely less on minions and leaves more time for research. He sees no need to spend much time learning the art of combat, his magic can protect him better than any blade possibly could.
Example of Play
While Mezteloc is searching for the lost Tome of Ra'Nesh-Xila, he encounters a couple of brigands that demand his money and his life. He quickly attempts to conjure a bear. The referee sets the difficulty at 9. Rolling the dice, the results are Multiply, 2 (skill), and 4 (luck). For conjuring, Mezteloc adds one to the skill roll to make it a 3. 3*4=12, a success!
After showing a magic word (???) and slashing like a bear, an ursine minion appears to dispatch of the brigands.