USCF rules require all players to keep score.  There is an exception if the player does not know how to keep score, but that is usually applied only for young children in scholastic tournaments.  If a player is not keeping score, the TD may assess a penalty.  The exact penalty is unspecified, but is usually a time penalty for the player who is not keeping score.

When either player has less than 5 minutes remaining on the clock, neither player is required to keep score.

(I think, but don't take this to the bank, that the 5 minute rule is void if playing with a 30 second increment.  In that case, scorekeeping remains mandatory in all cases.)

There are also some special cases for handicapped players and players with religious objections, but those are very rare cases.

"my religion does not allow me to keep score"

would be funny to see the reactions in a serious tournament :)

Thanks Meadmaker.  That's going to be weird at first. 

What I love about a tournament is the rush as well as making a brilliant move that causes the enemy to look stressed or sad. I love to see the hopes just die lol.

Go to a local chess club for some otb play ;Its more fun than online.

That's about what Fischer said too CFerrel, 'like to see them hopes die'

Cannot wait to go do some otb.  Must be a rush then, if it's better than online.

in the last round of the tournament the guy i was playing was suddenly down material in the middlegame with little compensation. This situation transformed him into a man possessed. He turned red and started sweating profusely from the armpits as he fought me tooth and claw for the rest of the game until i blundered and he won in the endgame !! That is an experience not easy to get playing online - the thrill of victory  ....and agony of defeat

Been there. Done that.  On both sides.  My favorite involved a game where I blundered a Bishop early, then fought desperately to hold on, taking a very long time to play.  I managed to stay even when he walked into a knight fork where I won a rook. Now, we were solidly in the middle game, but I was down to two minutes on my clock, and he had about 20. We were playing with a five second delay, and I checkmated him with 14 seconds left on my clock.

We were playing the tournament in a coffeehouse.  I wish it had been a bar.  I really needed a drink after that.

It is very rare that the situation comes up, but I have encountered it once.  The issue is with Orthodox Jews who are playing on the Sabbath, between sundown Friday and sundown Saturday.  I don't want to derail the thread with discussions of the minutae of Jewish law that dictates exactly when the situation might arise, but suffice it to say that it is very rare.   On the other hand, it is sufficiently common that I have encountered it, and the USCF did include a specific provision in the rules for it.

If anyone is further interested in the subject, start a thread, call my attention to it, and I'll explain further.  Otherwise, in the spirit of  this thread, just think of it as one more experience you could at least conceivably encounter OTB that you just can't encounter online.  I have also played against a blind player in an OTB tournament, and there were special provisions applied there, as well.

In the theme of things OTB that are a bit different in effect versus on the computer. I played against a fella with no arms. He sat on a stackable chairs to put his legs even with the table top. He used his feet to move the pieces, grasping them between his toes and to record his score. He was incredibly dexterous. It took me a bit to  adjust to the novelty of it. The obligatory handshake was a bit odd but accomplished nonetheless. You might play an armless individual over the intertubes but you most likely wouldn't know it and the experience wouldn't be near as rich.

As far as scoresheets are concerned in any tournament i have been in when one of the players reach 5 minutes left neither of the players are required to still keep score. Also there is no penalty if a score is written down incorrectly.I found it was nice when i did have a completed scoresheet but frequently i would make errors on it and was unable to replay the complete game. My very best result in a tournamet was my first one.I ended up with a rating which really was higher than my true strength. This did give me a nice feeling after the tournament but every tournament after that for quite awhile i would keep losing points off my rating which was rather a bummer.(My playing strength has always been somewhere between 1400-1599 and in my first game i somehow beat a 1900 player...i'm not sure which of us was more shocked.)