As a side note, some of Mac Sim's highlights when I'm DMing. I kid you not, he was not playing this Mac Sim as an intentionally bumbling dwarf. I made all the characters have an intelligence 12, because I didn't want humans who make informed decisions gaming the system.
In real life, Mac Sim's player has multiple doctorates in molecular biology and I forget what else.
You're not going to believe these things weren't done with him trying to play a dumb character. For some of them, he argued 20 minutes saying that was the smart thing to do.
-mouthing off (as a L5) to an Ancient Blue Wyrm Dragon, who melted his Dwarven artifact
-fell into the same pit twice (second time he could physically see it and still ran into it saying it was the shortest path)
-when a 15 year old dwarf boy (L0) challenged him for Mac Sim's bad attitude, Mac Sim took up the challenge, and using his Dwarven Artifact shield (which he knew was against the rules of a challenge cause the kid had nothing) killed the kid...who happened to be the son of a clan thane.

Rather than knocking him out.
-When they were passing beneath an acid rainfall trap, forgot to mention that he was going to direct the coated (protected) shield away from his teammates, so his teammates almost got a face full of acid.
-When meeting a party of adventurers who were scared of them, during discussions said "Screw you Paki (the other party) and didn't understand why Paki's party attacked them. This literally was a 30 minute discussion, and the player said "I say that to people all the time in real life and they don't attack me". We all tried to explain saying that in a bar and see what would happen.
-Multiple party deaths to him.
-After angering off the dragon, asking the dragon for a replacement item the next day.
-the character was introduced as an orphan who only had three friends in the world. The DM (me) dragged Mac Sim and his three friends into a big fight including the main heroes. The DM kills the three friends during the battle. After the battle, Mac Sim goes up to the heroes who saved him and asks if they need help....forgetting about the three dead friends. He remembers two hours later after the local constabulary drags away the three bodies. Oh well, says Mac Sim.
-He has insulted the local blacksmith/secret dwarven sorcerer so that his party was banned from buying weapons at the best shop in town.
-I've forgotten more, but you get the picture.
And let me repeat, he is not intentionally trying to play dumb.