The Nitty Gritty details: Fluff vs Crunch

Now, there are several approaches to RPG's. Many RPG's revolve around storytelling and complex lore (Fluff), like The World of Darkness, and D&D 5e/Next. Others are spent seeing how high you can (Crunch) the numbers to gain an optimal result, like D&D 3.5, the dreaded D&D 4e, and some others. Most rpg's claim that they try to find a balance between fluff and crunch, most rpg's also suck eggs at "balance". I grew up playing D&D 3.5 or Pathfinder, I've tried 5e and I'm not as much of a fan (need more crunch for this asian). I will deem both to be equally acceptable, my personal choices how I write set aside.

As for me I'm gonna try to balance the crunch and fluff. I am also probably going to horribly fail at balancing them, as those before me have done. I will mention feats, spells, abilities, and items by their names in their respective systems. When the party discovers and casts Identify on a longsword that erupts in flames and can shoot a fiery ray, I will call it a Flame Tongue, not "The mysterious flaming sword"

For instance both of these methods of describing the same event are entirely cool with me, though they are a bit on the **** side of both ends.

It has been the end of combat. Anders the 5th level Human Ranger has gained 3500 points of the experience for his efforts in the fight. This puts him to 15000 exp on the dot (convenient right?), which qualifies him for a level up. After rolling for his stats you add his class abilities. At level 6 a ranger gains Improved Combat Style, which grants him the Improved Two weapon fighting. This brings his previous maximum of 2 attacks per turn, to double, but with the same decreased attack roll that is inherent to two weapon fighting.

After the long and arduous fight with his foe, Ranger Anders sheathed his two swords. Through strife, valuable lessons have been learned. Through his fighting experience, Anders found a flaw in his technique that had led to inefficiencies in his attacks. In the following hours through practice, he discovered an optimal way to wield his two weapons. Each strike flew from his hands at a rate that was twice that of what he could achieve before only a day prior.

I will not personally dictate to each writer to focus on fluff or crunch. If you want to go through the trouble of developing a character with a fully filled out D20SRD or Pathfinder Character sheet, far be it from me to deny you the pleasure (and yes some masochists such as myself with Aspergers syndrome find numbers on a character sheet to be cool as shit). It is also equally okay and great for one to describe a character's abilities in detail. The amount of artistic license that you take is up to you for the most part, with the following caveat.

However please make sure to keep a sense of continuity and consistency about your characters. Unless there is reasonable context, your half-orc barbarian should not be rage-chucking magic missiles at the darkness, when before he was happily bashing walls with his warhammer that he has been happily using throughout the entire story. If you want to do crazy and absurd bullshit with your characters, far be it from me to discourage you. Hell, I encourage it as long as each event has a reasonable amount of context in regards to your last chapters.

Crunch should follow similar patterns. If you pick 3.5e (my pet edition), then you should generally stick to the same crunch, unless there are extenuating circumstances. A medium shortsword should deal 1d6 plus the characters strength modifier, a Greatsword should deal 2d6 damage plus 1.5x your strength modifier. If playing 5e, make sure your skill modifiers and proficiency modifiers are consistent (though 5e almost openly lends itself to purely fluff based roleplay).