Yes, for new players. But generally not, if they want to beat me they have to get better. A local match is much more fun if players are more or less on an equal level. If you play dumb on purpose your opponents will never get better, so they won't ever play on par. It worked well with any multiplayer game so far Smash Bros, Monkey Ball, Mario kart, with Tekken I was the weaker one and I gradually got better just playing multiplayer (I don't like Tekken in single player).

Never. Not since my five year old nephew said, "Sometimes you win and sometimes you lose and it just so happens that I am the very best there is at this game," when he beat me at the snowboarding event on Mario and Sonic at the Winter Olympic Games. I thrashed him about twenty times in a row to teach him a lesson.

When my friend pulled a victory on me in MvC2 3 weeks ago, he cheered and screamed as if he was given a gold medal, or something.  That's the first and only time he has/ever will beat me though.

No, I don't let others win.  I just, take stupid risks that leads to losses (in terms of mvc2) in every other game, it's a win they've earned.  I don't HAVE to let them, they are capable on their own... Except MvC2... lol.

I will let my son win.

I dont care about anyone else.

No. Because I personally don't enjoy winning if my opponent didn't do his best. It's not a real victory if it was given to me.

Although there's a caveat. Sometmes in online multiplayer if I see there's a guy who really sucks on the scoreboard I sometimes let him kill me (in the rare cases I am able to react fast enough to identify the opposing soldier and make the decision) because in the greater scheme of things he will not notice that he was rewarded a free kill.

Pretty much what Troll Whisperer said. When I play against someone that have never played the game I try to avoid the best teams or characters, but I never play bad on purpose.

However, this tactic can backfire. Who'd thought that Tunisia was an awesome indoor football team in Fifa '97?

That's the most logical option to even the odds in my opinion to make everyone satisfied. To give someone a pre-set handicap, but once the game is on all try to play their best.

That's what we did in Age of Empires 2. If we were say 5 clan members in a lobby we would put the 2 best players against the 3 worst, or use weaker and stronger civilizations to even the odds.

I almost NEVER play against friends. I only play in a team VS strangers online ,  VS bots or coop games like Left4dead/borderlands.

But if I play against friends etc I usually play newb mode/trick mode   (In MarioKart etc I drive slower  or try to do some stunts   in Smash Bros I try to not get hit for as long as possible etc and usually throw items at my friends instead of real fighting etc)

Sometimes, I do. Nothing turns a person off to playing than if they lose every single time. If you want to play, you gotta let them win.

This.

I'm extremely competitive with my friends at video games.  Even in co op.  I get pissed when losing at games online, but it's a whole different level if I actually know the person. 

Although I don't complain about losing as much if I suck at the genre.  First person shooters for example.  Facts are facts.  I am very bad at this genre, unless it's Unreal Tournament 3, then I'm pretty good at, or used to be until I've stopped playing the game for two years and get back on and the same people that I remembered playing before are still playing.