I think my current favorite character, and my wife’s character in the same game, sums up my view of MCing better than any examples from the games I DM.
Dresden is a Forest Gnome sailor (marine, mostly, but trained in haggling, navigation, and running the rigging and helm), inventor, acrobat, and a dabbler in magic. After his crew was killed by a necromancer who wanted to use their corpses as fodder in a sorcerer’s duel, Dresden got more serious about magic, and about using invention to more effectively kill mages.
He started with 3 levels of Rogue, Swashbuckler. I could have chosen Arcane Trickster, but it’s restricted in spell choices, and the illusion and enchantment schools don’t fit the concept that well, and he wouldn’t get rituals, which was more important than getting more spells faster. So, now he is a level 4 rogue, level 2 Bladesinger Wizard. He has a wolf pet that has a home brewed magic collar that lets her be his familiar (main benefits are more HP and he can ride her, but he rarely does bc he’s pretty quick, and he prefers to walk/run beside his allies).
Now, the character isnt conceptually a rogue/wizard. Conceptually, he’s that first descriptive sentence. Since we started, he has extrapolated from his understanding of abjuration and the ritual magic of enchanting items how to enhance his own physical prowess, and he’s basically used her to piece together how to reinvent an ancient Gnomish sword art that enhances speed, focus, agility, and martial prowess (bladesong). Certainly not a “power gamer” build. Those delayed rogue levels hurt. We also get 1st level bonus feats in our group, and Dresden has Skilled. He could have just gone Arcane Trickster, and grabbed Ritual Caster.
Ie, his “class” is Swashbuckler/Bladesinger or “Mage Hunter”.
Thumi is my wife’s Goliath Ranger/Druid. She started as just a pure Beast Master Revised Ranger, focused on Archery. Continuously, my wife was frustrated by how limited she felt by the ranger’s spellcasting, how many of the spells are concentration, the lack of versatility of being a known spells half-caster, etc.. She talked it over with the DM, and they worked out a plan to have her receive a vision showing her that she has always been guided by the spirit of the mountain eagle who guided her to save her family from orcish abducters in the midst of a terrible storm (folk hero background), the mother wolf whose cubs she and Dresden saved and adopted (reflavored unicorn spirit), and whatever the third one is (it’s late) from the Curcle if The Sheppard Druid subclass. Now she has one level of Druid. It’s not going to require special training with some Druids, it’s just the result of en epiphany moment where she fully realized how connected to the spirits and the land she is, and unlocked the path of greater Druidic power.
Also, as a DM, I want a story for everything, optional rule or not.