I've never been a huge tabletop guy, but I can give this a shot.

One time I was at my friends place and there was about 5 of us playing Risk. The game had been going on for like 4 hours and they were all starting to gang up on me to knock me out of the game, so I flipped the board off the table and went home. They learned their lesson. Nobody forms alliances against me ... nobody.

I was thinking more RPG stories but Board game anecdotes work too.  I have a different problem with Risk, noone wants to plays with me anymore. When playing Risk, I'm one of those alliance builders. You can ALWAYS count on my to up hold my word... HOWEVER, my friends eventually learned that I will hold to the letter of my agreements, not spirit.

My co-worker J and I were on the outs, dwindling forces. So I offered a deal 'I will not attack North Africa from Brazil. That we we can focus our defenses elsewhere, sound good?'   Naturally the offer of a reprieve of pressure was too good to pass up. 

We enjoyed our truce for quite a while, and finally we were both back in the game. I got a huge turn in of cards, and plopped all the troops in mexico. I invaded up through the americas, over to iceleand, europe, then down to my ally in africa. Once I passed his outter line, all his inner territories were near empty because of the truce. 

He screamed murder 'You said you wouldn't attack me there!' 

I just smiled, 'Actually, I said I wouldn't attack you there from here,' pointing to Brazil, 'I never broke my word.' Since then the others were wary of my, occasionally still accepting deals from me, be being  careful when they did. After a few more weeks of being undefeated, I wasn't asked to play anymore >.>

Ah yea, sorry about that. I really haven't ever played any RPG games like those and Risk was about as close as I could get. That is awesome how you managed to completely betray your friend's trust in order to gain the upper hand in a board game. That's the kind of thinking I try to apply to every facet of my life. People don't like me very much, but hey, we can't all be winners.

Hey once I pointed it out, they realized I could always be trusted, but only as far as the letter of the law :p So it wasn't really a complete betrayal >.> I never lied.

Hm, there is a story I could share that happened recently at our game. I have to add though, that only people who are familiar with the D&D 3.5 rules will understand how amazingly lucky we got.

We played a Dragonlance adventure and got into a fight with a group of Knights of Takhisis. They were armed to their teeth and outnumbered us, what followed was a really tough fight. One of the players went down  to -1HP and fell unconcious. I wasnt sure if we still could win that fight, so I called out to their leader, which happened to be the enemy that nearly killed our friend, and challenged him to a duel - I told him that If I would win, he would have to let us go; if he would win we would surrender. Since he was a knight (though an evil one I must admit), I thought that he will agree to the duel. The DM made me roll for diplomacy.. and I miserably failed. Thus the knight just laughed and tried to coup de grace our friend that was lying unconcious next to him! A coup de grace automatically scores a critical hit, so we were already certain that our friend was lost.. the DM made an open roll, so we all could see, and our friend was still alive with -9HP! The next round our bard managed to stabilize him, the fight went on and somehow we managed to win!

The funny thing is, that the player that just escaped death is still quite new to D&D, so it took him some time to realize in what a critical situation he was and that it was pure luck that rescued him :D

Ah, and thats why I love pen&paper rpg ;)

Maybe you'd have to know my now wife, but a bunch of us were making our characters, rolling dice and such.  She insisted she had to be a princess.  Just went on and on about it when we kindof ignored her at first and went about with what we were doing.  "Can I be a princess?"  "I should be able to be a princess."  "Handbook doesn't say I can't be a princess."  Smartass that I am I finally told her.  "Oh.  You're a princess all right.  There was never a question you weren't a princess."  15 years later and calling her a princess still amuses me.  ^^

... but this was the first to come to mind. A few years ago a bunch of friends and I were playing 7th Sea. We were trying to get wherever we were going but somehow we all started to hallucinate (I believe a glamour had been cast on us or something). Well, the entire group of us sees this big ol' dragon sitting in our way so, obviously we're all "Let's kill it! Despite that there are no dragons ever!" (I don't think any of us were Eisen so we didn't know about their dragon stuff). Anyways, so we're all hacking, slashing, shooting and generally being severely B.A. when one of our party makes their roll against the glamour (the rest of us kept blowing our rolls), strikes the dragon, and he "hears his sword clang off the dragon". His reaction = priceless.

"Clang? Dragons don't go 'Clang'!"

So then he snaps us all out of it and we realize we've been pounding on a big rock. Durr.

Maybe you had to be there, but I still laugh to myself when I remember this.

I was DMing for a large group of players in College. Somebody or other had brought one of those prewritten campaigns with them that they wanted to do. They promised they hadn't read it and didn't know what happened in it and yadda, yadda, yadda. I hate being limited by shiz like that, but I said okay and then proceeded to pretty much do whatever I wanted anyway and just used some of the characters from it. Eventually we got to a major plot point, and I completely diverged from the story because it would have taken my characters into Ravenloft, and I wasn't interested in DMing a Ravenloft game and none of us had talked about or agreed to making that change. Wouldn't you know it? The guy who had brought the campaign script pipes up "Hey! That's not what happened!" But yeah, he'd never read it. Last time I ever used a campaign I hadn't written myself.

Sorry for the delay in my promised anecdotes. My Backs gone out recently and I've been having problems sitting... or standing... or walking... or laying down... or... well you get the picture. I've got 2 lined up, just want to record them rather than write them.