pauljathome said:
If you allow this degree of customization then why even bother starting with a class based system? Why not just have a set of options that one can use to build a character, together with a set of pre-built packages to make life simpler for those who want it?
I would have absolutely no problem with such a system and it sometimes almost sounds like that is what 5th ed may be. And the whole "class based" is now basically just marketting hyperbole, a nod to nostalgia.
The class is still the main source of your abilities. Giving fighters the occasional ability to cast a fire spell (if they choose to) via some source (such as being dedicated to the Goddess of Fire) isn't any more class-violating than giving the ability to clerics via domains, or giving the ability to a rogue via Use Magic Device and wand. Because class isn't defined by what you cannot do, it's defined by what you're especially good at, and even if the fighter shoots fire from his fingertips (or his magic sword or his horribly charred hand that was anointed by the Goddess in his initiation rite, or whatever), that doesn't mean he isn't the dude who is the best in the party at hitting things really hard.
Ultimately, any class based system is just an ability package centered around a particular archetype. There's little in-game difference between saying "You're a fighter, so you have heavy armor proficiency and +1 to attack rolls with a weapon of your choice" and saying "As a Fighter, you have a +1 to attack rolls with a weapon of your choice, and the Defender theme, which gives you heavy armor proficiency."
The difference is mostly that you can swap out that theme for something else if you want, rather than having it as part of the class's baggage automatically.
I don't disagree that this has the potential to weaken the "purity" of a class. If someone is a fire-worshiping fighter who studied as an apprentice wizard and has the Arcana skill, the
Produce Flame spell once per day, and a +1 bonus to attack rolls with a weapon of their choice, that doesn't resemble the archetypal fighter as much anymore, but when you've decided that your fighter is loyal to the goddess of fire and studied as a wizard, you're already well out of the realm of the classic fighter archetype, so I don't see why that's much of a problem.
And if you want that strong archetype? That's why the default fighter has a background that gives them the Athletics skill, a Theme that gives them heavy armor proficiency, and a class that gives them a weapon focus. That's the archetype, built right into the class, for those that want the fighter archetypal.
I don't think the inability to cast magic is a defining trait of the fighter just like I don't think the inability to use a sword is a defining trait of the wizard. My mind easily welcomes sword-using wizards and magic-using fighters. I don't hear many objections about the former. Why is that one OK, but the other one verboten? Why can a wizard train a bit as a warrior and learn to use a sword without being defined by the concept, but a fighter can't train a bit as a fire priest and learn to use holy flame without being defined by the concept?