John’s lawful good. He’s got a strong sense of morality, justice and propriety—an image of “the way things should be.” And he is good. He can be an ass sometimes, but he’s in favor of saving lives and people being happy and all that jazz.
No way is Sherlock chaotic neutral, though. I’m not sure why people see him as being so erratic or whim-based when he’s demonstrably a highly organized planner with a strong sense of justice. It’s just his own brand of justice, not necessarily what society has defined. The thing about Sherlock is that he does have a well-developed sense of right and wrong, and a very strong conception of what a ‘hero’ is meant to consist of. He simply often chooses to act against his own definitions of ‘good’ in favor of efficiently achieving what he believes is the more valuable goal. I mean, he claims to only care about the case, but the entire reason he goes after CAM is because he finds him an odious bastard who preys on the weak and different. And despite convincing John that he has no emotions when it comes to loss of life, he’s furious at Moriarty for killing people.
So depending on what aspect of Sherlock’s personality you believe has ascendancy over his decision-making, I’d say either lawful neutral (if you think he’s more in it for the puzzles) or chaotic good (if you think he’s really in it for his own brand of justice). I’ve found the two have an interesting area of overlap.
Taking into account that entire history of activities so unpleasant that John wouldn’t even be able to love her if he knew about them, I’d put Mary at neutral evil, in a diffuse ‘does whatever seems expedient’ sort of way.
I think about alignment a lot, okay? I think it’s one of the weirdest and most interesting systems in D&D.
