…in games?
My wife ruthlessly beats our niece in tic-tac-toe, while I always let her win.
Which are you more likely to do?
If I’m forced to play with them, I pull no punches. You learn more by losing.
And when did you stop beating your wife?
Sometimes yes, sometimes no. I vary it up. I have a 6- and 4-year-old. The 6-year-old really doesn’t like to lose, but, well, I let her win some Mario Party games or whatever, but I also need her to learn that sometimes you lose, and you have to figure out a way to emotionally handle it. And that it’s okay to lose. And that games wouldn’t be fun if you always won. So, it’s always a balancing act between being nice and letting the kid win, and trying to emotionally develop them by getting them accustomed to the fact that sometimes you lose in a game.
I win the game if I can do it fair and square. Then I punch the kid in the face, as a means of celebration.
I try not to beat dogs too badly. I’ll let them win some rounds of tug-of-war.
It just depends. When I was teaching my son chess, I didn’t make all the best moves every time because I wanted to encourage him to keep playing. I didn’t always let him win, but I took it easy on him.
Embarrassingly, by the time he was 9 or 10, he was going easy on me.
Same here. Little Banjo took his chess seriously, and was killing me at age ten.
With cribbage, I wanted him to learn to enjoy it, and felt guilty as hell every time I beat him. Now he’s 24 and his squeeze is a Czech engineering student who loves cribbage (after we taught her), and they play all the time. He’s improved.
I’ve been beating my kids at Scrabble since they were sentient enough to play. I was brutal. They are all good players now. I still win.
My DIL is closest to beating me.
We’ve had 2 tournaments while locked down. I didn’t win every game but my points held up to win both tournies.
They don’t wanna play with me anymore 
I kicked my nephew’s butt at Mario Kart last time I saw him. I told him I wasn’t going to go easy. However, I suspect that in a year or two he’s going to kick my butt, due to the fact that kids can play games for hundreds of hours, and that kids have better reaction times than the 40+. So I’ll take my wins when I can.
I’ve never let anyone win. My nephew (age 14) has only just gotten to the point where he beats me sometimes at chess, and I don’t think it’ll be too long before I struggle against him.
Oh, and moving to the Game Room
I’ve never let anyone win. My nephew (age 14) has only just gotten to the point where he beats me sometimes at chess, and I don’t think it’ll be too long before I struggle against him.
Oh, and moving to the Game Room
I let my youngest two win, and the older ones play fairly. As they get older, they’ll be held to proper standards, but it’s good learning for them to play the game and encouraging for them to get points.
Example: When we’re playing Boggle, we’ll let those kids get points for words they find and spell correctly even if other people have those words. They only know simple, short words and they’re the ones that other people will likely have, but if they keep getting no points, they’ll just get discouraged and quit and never really learn to play for real.
The only time I played a competitive game with my niece, I couldn’t let her win because I couldn’t figure out the rules - she wanted to play ‘Crazy Eights’, but the game she was playing was more like Asshole, but not quite enough like it that I could just play Asshole… (I then tried to teach her the proper rules of Crazy Eights, but she was having none of it.)
When they wanted to play a serious game like chess, I played them seriously. When they wanted to play a board game, I let the roll of the dice lead the way, and didn’t try any heavy strategizing.
If they’re old enough to fully understand the rules, no mercy. But if I like them, I’ll show them how I beat them, afterwards.
The only game I get obnoxious about is Scrabble. I am a good speller with a surprisingly large vocabulary, and I do not suffer misspellings. (also, Monopoly, but I hate that game and I have decided that I really have no need to play it ever again)
When my kids were learning to play chess, I would give myself an explicit handicap at the start - take, say, a knight and a bishop of mine off the board before the first move. Then play as hard as I could.
Scrabble rules with kids is “no playing a word unless everyone at the table knows it”. Apart from that, fair game (well, we also give advice actually. But that’s above board, no playing low-point words ourselves when we see a better option)
Once we graduated to Euro-boardgames and the like, just beat them as hard as I could as often as I could manage it 
I agree with the “Take it easy” part. Kids need to learn how to lose gracefully, and how to use that experience to get better at games the right way. However, in some games, just stomping the bejesus out of them without mercy is counterproductive. The difference between me and my kid in Scrabble is so gargantuan that if I just go balls to the wall, she’ll be losing by 200 points in twenty minutes and I’ll be blocking all the best moves. I can stay just ahead of her, not letting her win but not humiliating her. She won’t enjoy it and won’t actually learn how to play. But if we’re playing Ticket To Ride I may as well try my best; the game is less conducive to crushing your opponent like a bug.
There was that time I played Russian roulette with my neighbor’s toddler. I was damned if I was going to let him win.
What I sometimes do is play with extremely little pondering or strategizing. Against a very young kid, I might pick my move within 3 or 4 seconds, rather than really think about it. So I’m still playing to win, but any advantage from my greater experience is greatly diminished. It works really well for games like Connect Four, checkers, chess, and others like that where a lot of the adults’ advantage comes from being better able to anticipate and think ahead. It would probably work for Scrabble, too. And you can tailor how much pondering you’re doing in response to the kid’s skill level, and they don’t know you’re doing it.
One unintended plus is that the game moves much faster, so you can play a lot more rounds in the same amount of time.