Now to change gears and returning to a topic I mentioned here I want to talk about writing genuine autistic characters and do it in a manner that is respectful and about disability in fiction and role play.
First thing you need to be aware off is how educated you are. If you know little about autism then you should do your homework before you create an autistic character. It's probably good for you to volunteer and work or spend time with autists to gain some experience before you start constructing one. If you are autistic yourself, try playing around with different levels within the spectrum or co-morbids. Like if you are Asperger, try playing an Aspie that has seizures, or a character that is PDD-NOS with a savant talent. Broaden your horizons.
Now as autistic fiction writer, we have obligation to provided a few tropes to RPers and readers that are non autistic. Yes these people expect stereotypes and key-words to identify the autistic person. Now as an autist myself I do get irritated when people see the autist and then pull the Goldilocks Rebuttal. Either he is "wrong" and I am playing the character "wrong" or he too "autistic" to be any use in the fic/game or not autistic enough and they can't tell. The latter shows up with my HFAs once in a while. Cori and Wilson are on the high end of the spectrum both are 'superheroes' (Wilson has clairaudiance and the ability to communicate to Angelics and Demonics, Cori can cause hyper-growth with plants and can control them, Ollie is the only non-verbal and is a powerful psychic) so the superpowers act as balancers in sense allowing them to participate in big events (villians and shit) but still be disabled and yes their autism does interfere with them saving the world. Tikaani is my only autist OC without a huge balancer.
Now what is a balancer? A balancer is positive trait that compliments the negative traits. In other words it balances them. If you have autistic character that lacks a balancer, sure you can write him but he would be hard for NTs to relate to or like and for some autists might be grating for a character to have too many faults and feel like he is something to pity.
However there are some tropes to be aware of when doing a fictional autistic character. While balancers are great to even out the flaws and strengths of your character the "Rainman" trope is common tool for autistic characters even Tikaani borderlines this with his perfect rhythm and his ability to repeat conversations verbatim. Ollie has this by default as he is telekinetic but he is also non-verbal and no he doesn't communicate by telepathy (he uses an augmented communication device). Don't over use it to the point that the disability because irrelevant and useless and it's ghosting this trope. Tikaani also rides this trope a few times, while that trope can be a balancer it can be done poorly to the point the character becomes something of an insult.
Occassionally you might have autistic character with the Handicapped Badass trope. Now this is very hard to execute in fiction. Because you don't want to over do it and thusly wind up with this, and like Crouching Moron; Hidden Badass, have a character that is joke. Chiko rides the former trope occasionally, he's an amputee so airbending with one arm is kinda badass. Best way I know for executing this is to have the autist stand up for himself. Finally put his foot down. \
Now also you need to keep aware not to over do with the fact Character B is autistic you can mention it upon introduction but let actions speak. Also don't jam said autistic character with over done NT stereotypes on how autistics act. While you can have a few because to be very frank, NTs are clueless when it comes to autistic characters even with those with siblings on the spectrum. But don't over jam them to the point your hitting the Sympathetic Sue trope and or the character become again a joke. Not every autistic character has to hate being touched. Tikaani communicates mostly with touch only Cori and Ollie don't like being touched or hugged. Not every autist is good with math or science. Wilson is obsessed with mushrooms and botany, but he the only "science orientated" autist I have. Tikaani might be hyperlexic, and Ollie is also hyperlexic but Cori took forever to learn to read. You can make your character autistic but don't worry about making them too subtle. Just understand that every autist is unique.
Finally don't shove your disability politics into your character so he won't be come a mouthpiece. Tikaani might be anti-cure if he was in our time period. He also very much a self-advocate, yet is also very very quite about his opinions and probably won't be an activist or might think neurodiverse activists as obnoxious zelots. Ollie was a bio-med child and is something close to pro-cure. Yet he is worried if being cured mean he will lose his powers. Wilson is very apathetic to cure and probably sees himself as cured. Cori is probably the only one that would actively embrace neurodiversity but would probably advocate cure for low-functioning autists. As you can see none of my character share the same politics I do.
Finally, I am still working hard making a believable autistic character I will definitely accept critique as long as it's constructive.