This is why I say 'usually'
There are exceptions and hybrids, just to make the whole thing worse.
Witcher is definitely an RPG, despite there only being one character, because the emphasis is on 'player choice, characterisation and freedom of action'.
DD is a hybrid between an RPG and an ARPG, being strongly action-focused but still offering some pretty good choices and player options.
Jade Empire is the worst, though, because it's a hybrid between all three!
