My PCs are often stupid... but so am I. Here are two stories.
One, my very first time playing DnD. 2nd Ed. I was a halfling thief with a high Charisma, 1st-level. We had to travel somewhere by boat, one big enough (barely) to hold our horses, so I went below the waterline to practice my knife throwing.
I rolled a critical failure. I really didn't think a knife could go through the hull like that. I didn't want to tell anyone I was sinking their boat. I'd get in trouble, after all. So I went to visit the horses, collected something EN's granny wouldn't want to hear about, and used it to plug the leak.
It didn't work. So I had to tell my friends what happened anyway. I left out what exactly I had used to plug the leak. I implored the other PCs not to tell the captain what happened, instead simply helping me fix the boat. Perhaps fortunately, they didn't listen. They went straight to the captain.
The captain, and the other PCs, were simply amazed at what they saw. Water leaking through a crack in the side of the boat's hull, plugged up by straw and ... other substances, which had ended up smeared all over the wall and smelling terribly.
The captain easily fixed the damage, and charged me a huge amount of money for it. I had no money. Fortunately the friendly fighter had some, so I had to pay him for wrecking the boat and getting horse doings all over the place.
The second is more embarassing than outright stupid. I hope. I'm used to playing characters who don't die. I was playing a 3.5 gnome wizard in a campaign DMed by Mr. T., who was annoyed that I bragged my PC couldn't be killed. (I was right, though.)
We were players in a Call of Cthulhu campaign. Invincible characters? No. We didn't even get to see our character sheets. But no matter, I was too smart to let my PC die. In fact, I'm such a genius that I managed to win a bonehead award for what I did in CoC.
In my defense, I was pretty smart until a kid delivered a magical letter to me. Not that I knew it was magical.
We were tracking down Cthulhu cultists, and (unknown to us) a Cthulhoid monster was hunting them as well. It looked for anyone who had received a magical letter. Anyone who received a letter (always the first person to get it) was magically marked. The letter had a bright red mark on it, which turned black as the victim's time approached. Getting rid of the letter wouldn't save the victim. However, solving the mystery could maybe allow you to survive.
I received the letter, looked at the mark, paid the kid a tip (or tried to, but he ran in terror - wonder why?), and put it in my pocket. I promptly forgot about it. (If I had looked, I would have seen the color change, realized it was magical, and maybe did something about that.)
Later on, we sent one PC to interview a cultist, an old lady, who lived in an apartment building. She charmed him and sent him away. He told us she was an innocent old lady. However, I wasn't convinced - he was acting too oddly. If only I had believed him, I probably would have lived. (She had also received one such letter, but I didn't know this.)
So here comes the final event. I was marked for death and didn't know it. Myself and Mr. T went to spy on the old lady, without backup. (So maybe Mr. T. wasn't that bright that night either.) The monster would randomly seek whichever of the three victims had been marked, and now it had two marks really close together.
We parked by the curb, and after a while the monster grabbed our car from beneath (from a sewer), picked it up, and started shaking it. Mr. T. and I jumped out. The monster swiped at me. (I figured it could only swipe at one person, and targeted me at random. I was quite wrong, as later events would prove.)
Mr. T and I ran into the old lady's building. The monster pursued us up the stairs, Mr. T. slightly in front. The monster swiped at me again ... but of course, it made sense, since I was slightly more vulnerable to it, being in back and all.
At the top of the staircase, Mr. T and I split up. The monster just happened to follow me. I ran to the old lady's house. I banged on her door. I had this brilliant idea that this evil cultist might rescue me or somehow defeat the monster. She opens the door, sees the monster, and freaks, slamming the door in my face and bolting it. At this point, my luck deserted me. The monster caught me, then had a problem. Should it eat me first, or should it save me for later? Alas, it thought I was the best meat, so it ate me. Apparently, I tasted real good.
Mr. T. started laughing hysterically at this. I was so brilliant I had performed a series of mistakes leading to my demise only two sessions into the CoC campaign. Then the GM informed me of the additional mistake invovling the letter.
Mr. T. never managed to kill or even seriously injure my character though, even though everyone else got beat down at least once in their career. Heh heh.
