Quote Originally Posted by rgrekejin View Post
Yeah, this seems like an eminently reasonable conclusion to me. Rich has used very few non-core things, and almost all of them were in throwaway gags that specifically drew attention to themself (with one or two very notable exceptions).

By my count, here are the instances of non-core classes:

1. Ninja (Therkla, Azure City ninjas, Goblin ninjas. Complete Adventurer)
2. Dashing Swordsman (Elan, Julio Scoundrel. Third-party sourcebook)
3. Unspecified Psionic classes (Blue goblin, The Little Psion that Could, Psteve the Psion from the Dragon comics. Expanded Psionics Handbook)
4. Unspecified Incarnum classes (Redcloak mentions one, one appears as an intern adventurer in the Dragon comics. Magic of Incarnum)
5. Spellthief (Intern adventurer in Dragon comics. Complete Adventurer)
6. Warlock (Tavern Brawl. Complete Arcane)
7. Possible Soulknife (Tavern Brawl, Expanded Psionics Handbook)

So, that's a total of only seven classes, spread across only five books (only four of which even actually exist), and some of those are from the Dragon comics, whose audience would be more likely to know about those specific classes than a general reader. There are of course additional non-core shoutouts (Redcloak's three skeletal minions, Tsukiko's non-core spells, Thog's Dungeoncrasher ability and the acid-born shark come to mind), but they've been specifically called out each time, either in-comic or on these forums by Rich. Something as substantive as the actual class of a major antagonist would be unlikely to rely on a niche rulebook from the 3.5 system. Sure, Therkla was a major player in the comic, but she was a ninja, and everybody knows what ninjas do, even if they don't know the DnD rules for them. The things from the Tome of Battle are rather clearly invented just for DnD, and would not be immediately clear to someone who wasn't familiar with that rather specific niche splatbook. So unless we at some point get specific in-comic mention of Tarquin being a martial adept of some sort, Rich explicitly says he is one here, or he does something that simply cannot be explained through any other mechanism, Tarquin should not be assumed have a Tome of Battle class.

...wow, that whole wall of text was only vaguely on topic. But I took the time to write it, so I'm going to post it anyway. Sorry.
I'd further note that, as I've said in the past, we really don't know whether the ninjas seen in the comic actually had any sort of ninja class or not.