Maxperson
Morkus from Orkus
That's why I leave it to my players how they roleplay being below average, but some method of being below average is expected. I also don't mind the PC having inspirations sometimes. And of course the player can talk to other players out of character figuring stuff out.One of my favourite characters ever was a priestess with an Int of 8, and basically I did not play her dumb for what was a long campaign, because that would have been incredibly boring in short order. But she wrote everything down, on little pieces of parchment, that she sometimes lost (sometimes with hilarious or dramatic effect), and she sometimes (but not too often so as not to annoy the other players) asked other members of the party to summarise the situation for her. And that was it.
My partner is an orthophonist, who works with all sorts of people with impairment, cognitive, speech, etc. from very small children to elderly (or not so elderly, which is really sad) people who have diseases or accidents, etc. and there are almost as many factors as there are people. It's all well and good to say "impaired mental acuity", but what does it really mean in the game, knowing that it's still a game and should not be used derisively.
A guy I used to play with was probably in the 8-9 intelligence range. He wasn't that smart, but his main issue was processing speed. During 3e, we were once in a fight against Kostchtchie and some other giants and his barbarian was about to be smashed to a pulp by Kostchtchie himself. My wizard seeing the situation used a limited wish spell to place my Ring of 9 Lives(which healed the wearer when "killed") on his finger so he would survive. After the game he came to me and asked me if I came up with that right then. I told him yes. He said that it would have taken him a week to come up with that, if he came up with it at all.
That comment got me paying more attention to people who weren't as smart and watching how they do things. A lot of it really is just processing speed. It takes them longer to come up with ideas that smarter people come up with quickly, and many times they give up before they get there. It's not that they can't do the things the rest of us do, it's just harder. Which brings me back around to being okay with low intelligence PCs having inspirations and sometimes coming up with solutions to problems that a lot of people would think that a low intelligence person couldn't come up with.
I take care of this. Since a non-genius literally can't ever play a PC like that, I will often just give the genius PC information without a roll. Or if I know that there is a connection, but the in game links are tenuous and hard to see, I'll sometimes link them and let the player know that his PC sees the links. It's the best I can do to help the PC be the genius its int stat shows.And there is the problem the other way around. How do you play someone with a genius-like intelligence ? This is why, honestly, especially for this stat (but also wisdom or charisma), I feel it's usually better to leave it to purely mechanical effects...