Rank Based Die Rolls

While I maintain the (strong I admit) opinion of not using dice to determine a character's success or failure when taking a certain action, there can be those times where a dice system can prove useful, even necessary. My stance against the use of dice is the result of past experiences during roleplay: I once had a character who was a total rookie, but in a certain situation they were acting like a true master in their craft, thanks to extremely lucky die rolls (which isn't necessarily a bad thing). I also had a well trained warrior who, due to successive bad rolls, acted like they had never even held a weapon properly, let alone use it.

So, I came up with the following dice system that uses the ranks mentioned earlier, with the intent to alleviate unfairness such as the above, which may seem complex at first glance. Its difference from other known systems is that instead of giving modifiers to each roll, it gives each rank its own dice as follows:

Novice: d20
Apprentice: d18+2
Journeyman: d16+4
Expert: d14+6
Master: d12+8
Grandmaster: d10+10

Now, all a player needs to do is to roll dice based on the rank of the attribute that governs the skill they want to use.

For more information on attributes and the skills they govern, you can check Appendix I.
Or if you need more information on skills and their governing attributes, you can check Appendix II.

But what if there are modifiers affecting a character's skill? How are they incorporated in a die roll?

If there is a buff (or debuff) directly affecting the level of an attribute, it should be applied first in order to determine the effective attribute level and its new rank (if it changes at all). Such direct buffs (or debuffs) aren't applied again separately. All other modifiers are added to the above die rolls as in other commonly used dice systems (like D&D).

The result of such a roll is called Attack Rating (AR), even when the action isn't really an attack, just for simplicity's sake.

An example to make this easier to understand:

Shudasha wants to use her maul to attack an opponent during combat. The maul is a blunt weapon and the respective skill is governed by Strength. Shudasha has Strength of 15, which makes her an Expert, and thus she will roll d14+6.

Shudasha then receives a buff that increases her Strength to 17, effectively making her a Master for the duration of the buff. In this case, she will roll d12+8 instead.

At another time during the same battle, Shudasha receives a debuff that lowers her attack by 1. Her Strength remains at 15, thus she also remains an Expert. In this case, she will roll d14+6-1 or d14+5.