Assign each to a color of magic. Whenever you do something using that color of magic you roll the die you assigned to it
The baseline you need for a success is 4 with – anything less than that and you may still succeed but not with the ideal results
So for example I wanna summon a Grizzly Bear but I’m real bad with green mana. I roll a 2 on my D4. Maybe I summon a weak Grizzly Bear that’s basically a 1/1 (not that this RPG uses stats like that probably). Maybe it’s a sort of illusion and vanishes when attacked. Maybe it turns on me. Maybe I just straight up summon some other green animal instead
You have five dice to assign to mundane skills as well. Stuff like longsword, athletics, first aid, guitar, etc. They work like the above except they govern doing stuff that isn’t magical. Probably anything outside of that stuff you roll a D4 on
Having advantage means you roll a die of the next unit up (for advantage on a D12 you add 2 to your roll). Disadvantage means you roll the next die down from what you would normally (and disadvantage on a D4 means subtracting 2 from the roll). So for example advantage on a D4 means rolling a D6. Disadvantage on a D10 means rolling a D8
BUT not every blue mage is the same. Maybe you’re better with artifacts. Maybe you do counter and control magic. Maybe you summon illusions. You have a specialty (maybe, maybe, two of them). The DM should take this into account when determining the difficulty check for a roll and adjust it lower for something that falls under your specialty
So, as many have already speculated, Amonkhet may just be a “planeswalker factory” set up by Nicol Bolas. However, the purpose of devising such a thing has not been as well theorized. (TL:DR version at end of post)
First, some background to get everyone up to speed. We already have evidence that Amonkhet is an artificial plane created by Nicol Bolas. I figure this is to prevent unwanted travelers to interfere with his plans. I assume an artificial plane is much easier to “hide” amongst the multiverse. As far as we know, only pre-mending walkers were ever powerful enough to create an entire plane on their own, so Amonkhet is probably pretty old, which means Bolas has had plenty of time to mold the plane and its inhabitants to his will.
So, the “planeswalker factory” in question is the Trial of the Five Gods. We’ve learned that all denizens of Amonkhet work their entire lives for a chance to partake in this trial to appease their God-King, presumably Nicol Bolas, and earn passage into the afterlife. We also know that sparks are most likely to ignite when the individual is put into an extremely stressful, potentially life-threatening situation. This trial could be just that. Putting individuals through tests to awake their latent spark. And since no-one is ever expected to return from the trial (moving on to the afterlife and all) no denizen of the plane can refute it and Bolas gets to do whatever he wants to the survivors.
So, for a while people have assumed Bolas has been collecting these planeswalkers as an army to use to conquer the Multiverse. However, we have been ignoring his greatest desire, to regain his original power. What if, instead of creating an army, he is stealing and storing/consuming all of the sparks from these new walkers and using them to regain his own lost power? We’ve seen sparks transfer from one to another (i.e., Venser and Karn) and sparks can exist independent of the person they originally belong to.
TL:DR: Bolas is using his “Planeswalker Factory” to create and harvest the sparks from new planeswalkers in order to make himself more powerful.
Liliana Vess is one of most recognizable MtG characters, a powerful magician, human planeswalker and a master of necromancy. She is using black mana to reanimate the dead, corrupt the living, and unlock power from death. Known of her beauty, she appears to be in her 30s, she is actually centuries old.
She is searching new place to live in, so if interested in buying her – she is available in my Etsy store here [click click]