for what reason do you play chess?

"When you play chess, you can get a taste of your opponent." --Hannibal Lectur,MD.  Take it from a doctor, it's good medicine.

Go to the pub?

When I'm not feeling well, with a headache, asthma or just plain stressed out, chess will always transport me to a wonderfully absorbing place free from troubles and pain.

Chess is wonderful "escapism" Ziggyblitz but whisky is only mechanism that transports to the places you speak of.

To punish myself.. some people drink.. some people use drugs.. I play chess 

You could do all those things. 

Ever tried Scot's whisky?

Um, no. Ever played golf on 'shrooms?

Pass the Glenfiddich... I need a drink to help me think of all of the reasons I play chess...

For love of the game! I learned the game when I was a little kid. It always came back around even tho, I stopped playing for a while. Chess has been one of my longest, least inexpensive hobbies.

For lack of a girlfriend.

Enjoy playing.

I play to crush my enemies, to see them driven before me, and to hear the lamentations of their women.

Seriously, I love puzzles and every chess position is a puzzle to be solved.

It's something I enjoy that will actually have an impact on my future.

I enjoy it because it keeps me in a logical/analytical state of mind, which makes me feel comfortable.

It's a fun way to stimulate my mind. I don't play OTB, though.

I dont know .. chess have the power to make me play again and again.But  from my reasonable point of view is a waste of time and a vain game

Chess provides a good measue of your state of physical and mental health. If you're playing worse than usual, a little self-reflection will reveal that you are sleep-deprived, run down, or at least distracted. If you're having a great day at chess, then your health is probably fine. In this sense, chess is a type of yoga.