When you make your move, look her in the eye and let out a sexy groan. Hopefully she will do the same and the result will be immaterial.
Should I let my girlfriend beat me in a chess tournament?

give her a fighting chance. hurry, hook her up with a_l_i_v_e!
Why would you want the girlfriend to receive nothing but ambiguous advice. It would only complicate matters.
love is complicated ...
But it doesn't have to be moronic.

Go over "opening prep" (1. f3 2. g4 if she's playing white, 1... e5 2... Bc5 3... Nc6 if black) before the tournament then scholar's/fool's mate her ass.

Win but give the prize to her 9KingHenry

I also witnessed a tournament game (I was 14 years old and I'm not making this up) where a lovely blonde was losing badly when she suddenly looked at her opponent and said, "I'll sleep with you if you resign." Some guy was walking by at that exact moment and almost fell over when he overheard her offer. In this case, even though you're winning, resignation might be acceptable.
If you have sufficient reason to think that it'll get you laid IM Silman approves! (Quoted from http://www.chess.com/article/view/when-is-the-right-time-to-resign?page=2)

I know your heart is in the right place, but if you start acting in ways to her that are not honest, she will learn to not trust you if she finds out. How about helping her improve her game instead?

I know your heart is in the right place, but if you start acting in ways to her that are not honest, she will learn to not trust you if she finds out. How about helping her improve her game instead?

ssakash wrote:
play like you have no interest in winning then, the results will be formidable.
You mean losing will be rewarding?! Not quite the case.

It's actually a philosophical question.
My opinion depends on the girl. Is she hot and dumb? Then let her win.
Is she intelligent or savvy enough to know that you are letting her win?
I would say do not let her win in that case. Then applaud what she did right and show her what she did wrong. Compliment her analytical ability. Do not be a wuss, but be loving and fair. Treat her as an equal. If she has brains she will appreciate you more. If not, she is not worth you. The fact that you asked this question shows you care. IMHO.

In life you can't have everything.
True. Yet there is no caliber of woman you cannot have.
Believe it and it will happen.

Olympian256 wrote:
In life you can't have everything.
But you can have both of them. The girl and the win.
I think deliberately losing a tournament match is probably grounds for a lifetime suspension from whatever chess federation you belong to. Not to say you would be caught, just pointing out the degree of ethical problem you are having.
Also, to correct the nonsense advice being given here. Letting a girl win only works when it is OBVIOUS that you are letting her win. If a girl ever thinks that she is actually better than you at something, you will drop a notch in attractiveness for her. Girls are attracted to guys who are superior to them.
Just play honestly. I'm sure she would be able to tell after beating you that you were not trying at all.