Fakedit:
Nope Rolan, anti-paladins are a thing since 3.0 (and kinda before, but not really), they were initially a prestige class, then WotC decided to make them a main class (oh how I hate the class bloat.)
I don't doubt the 3.0 thing, but they aren't in the openSRD except as the (slightly different) Paladin of Slaughter.
Unless they were republished in a 3.5 book, I'd say they were supplanted by the 3 variant paladin classes which are in the 3.5 openSRD. Which I assume are in the 3.5 Players Handbook, but I really don't know...
Of course a lot of 3.0 content can be used in 3.5 (took me forever to realize that the Book of Vile Darkness was 3.0. And maybe the BoExaltedDeeds, but maybe not?? whatever). It ought to be discouraged when there is a close 3.5 equivalent, though, to be considered an update.
I think the Blackguard was traditionally also referred to as an anti-paladin
This may be what is meant
Noooo no no, Blackguard is a specific thing which is ACTUALLY the opposite of a paladin. Paladin of Slaughter, or "anti-paladin" as it's called, is just a paladin with a different alignment. A blackguard is one who has forsaken alignment. Paladins who fall can get bonuses for becoming blackguards, but I think technically anyone can do it.
It's kinda like a druid, but you're not championing the world. You're just fed up with alignment and basically serve your self. Some of the interesting characters in our campaign were blackguards.
@Neonivek
That's an interesting perspective, though mine's different.
In the one campaign I've played (it lasted two years though), there was a lot of BoVD and BoED. Both good and evil people got blessings from the primal forces of Good and Evil. But, honestly? Evil people got better boons. The corrupt spells of BoVD were just better.
Evil was a temptation because it offered, upfront, significant power increase. Not to mention that the lord-devils, Asmodeus in particular, were offering tantalizing deals of their own.
Good was something we (well, SOME of us) followed at first for its own sake. In a way, I followed it because only a good character would truly care about deposing the evil empire and the devilcultist city.
It was rough since the other players went arcane-neutral or crazy-evil and were either sympathetic to the evil lich empire, or omnicidal respectively...
But I guess my point is that good is most meaningful when it *isn't* a mirror to evil. When evil offers blatantly superior powers, but you refuse, because god DAMMIT it's the right thing to do. If anything, the reward you get should be the goodwill and support of the downtrodden.
Dunno if I mentioned this, but the campaign crumpled a couple sessions after I left. Possibly because a greedy cannibal ogre mercenary and an insane klepto mage didn't have much reason to actually fix shit.