what is exactly three fold repetion

That position is impossible to reach through repetition if black has castling rights.

Still, your point remains if you throw in a random knight in a useless position :)

Thanks for the help but still confused lol

Well, do you have any more, or more specific questions?

The answer to your original post is that both players have to come back to their same position (imagine taking a picture of the chessboard at different times), although it could be through different moves.

Someone can't just move Ng1-Nf3-Ng1-Nf3-Ng1 and claim a draw on the third move if their opponent is playing normal opening moves.

All that stuff about en passant, castling rights, and who's on move just defines how two positions that look the same might still be different.

Why do players want the 3-fold should be the question.

I've seen players give away a win for a repetition.

I think for practical purposes, if you are still new to chess, the only 3-fold repetition you need to really concern yourself with for now is the simplest one - i.e. both players just play the same moves back and forth 3 times and then agree to the draw (or technically I suppose one side claims it).

As described by various people, 3-fold repetition does not have to be consecutive of course, but recognising a 3-fold repetition spread across 20 moves is quite challenging and far less common in a practical situation than the consecutive move repetitions.

I did have one of the 20-move or so repetitions myself recently when an opponent was trying to win on the clock in a totally drawn bishops of opposite colours ending. We made lots of moves ( < 50 ) and I offered a draw 2 or 3 times and on the final occasion what I thought was to be a draw offer turned out to be a claim on three-fold repetition that I wasn't aware of.

 Nice! 

Here's what some people get confused

This is not 3 fold repetition:
 

White was repeating his moves, but the position itself was never repeated because black continued to make unique moves.

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The following is 3 fold repetition
 

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And another example of 3 fold repetition
 

What's a repetion?

The phrasing is a little funny isn't it?

2 repetitions make a position appear 3 times. So it's more like two repetitions make a draw.

Maybe "3 fold repetition" could be seen a short hand for "3 occurrences of a position due to repetition." Or something like that.

FIDE:
9.2

The game is drawn, upon a correct claim by a player having the move, when the same position for at least the third time (not necessarily by a repetition of moves):

1. is about to appear, if he first writes his move, which cannot be changed, on his scoresheet and declares to the arbiter his intention to make this move, or
2. has just appeared, and the player claiming the draw has the move.

Positions are considered the same if and only if the same player has the move, pieces of the same kind and colour occupy the same squares and the possible moves of all the pieces of both players are the same. Thus positions are not the same if:

1. at the start of the sequence a pawn could have been captured en passant.
2. a king or rook had castling rights, but forfeited these after moving. The castling rights are lost only after the king or rook is moved.

Perhaps "Three-fold Replication" might be more accurate?

Interesting. Good point (once again) it doesn't have to be repetition of moves.

So then the etymology of the phrase "3 fold repetition" would be interesting to look into. Seems to be not exact at all.

Again though, the 1st replication is the 2nd appearance.

The 2nd replication is the 3rd appearance.

Maybe "3 fold occurrence" or something, as the first occurrence is also the first appearance. 

Yeah, it's hard to find an exact term of phrase.  I suspect the original intent was to avoid perpetual forced moves (forced in the sense that other moves would lose) by limiting them. Somewhere it changed to something else.  I not sure of its value in its present form. A trio of snapshots of an indentical postion, *in and of itself*, doesn't seem to indicate anything drawish... unless I'm missing it.

That's an interesting thought, challenging the usefulness of the rule as it is today.

At the very least you could say that a player who causes a position to occur 3 times has failed to make progress. Even if they're easily winning otherwise, they've shown some small incompetency.

I actually had a small dispute in a casual game (with another tournament player who knows all the rules) when I claimed a draw like this. His position was overwhelming, but he had been lazy and after a few spite checks caused the position to repeat 3 times (several moves apart, but it was easy to remember).

That actually contains 4 positions which each occurred 3 times.

It was a draw for the first time after 4...Ng8 (the first 3 fold repetition).

Well the rule doesn't seem to serve its purpose, if I understand the purpose correctly. And if I do understand it, I don't know if it needs to be abolished or just refined.

Hard to say. The only negative circumstance that comes to mind is when a player is clearly winning and inadvertently repeats the position.

If that's the only case I think the rule is fine as it is.

Some cases of separated repetitions (as in the rook endgame I posed in page 2) would be a nuisance to have to play out to the 50 move draw.