Suppose I nudge a piece back on to the center of its square using a light tap with the back of my little finger. Will this constitute touching the piece within the meaning of the FIDE touch-move rule?
If on my turn I adjust a piece on its square without saying "J'adoube" or equivalent do I have to move it?
Article 4.3 of the FIDE rules states:
Except as provided in Article 4.2, if the player having the move touches on the chessboard, with the intention of moving or capturing:
So, if it is clear that my intention is merely to adjust the position of one of the pieces then touch-move does not apply. Of course it must be done on my turn otherwise I am liable to be penalized for disturbing the opponent.
EDIT (2018): The latest 2018 edition of the FIDE Laws of Chess contradict this -
4.2.1 Only the player having the move may adjust one or more pieces on their squares, provided that he first expresses his intention (for example by saying “j’adoube” or “I adjust”).
4.2.2 Any other physical contact with a piece, except for clearly accidental contact, shall be considered to be intent.
So, if I clumsily brush a piece with my army or knock one or more pieces over this does not count as intention. However if I adjust a piece without saying "j'adoube" or the equivalent then I must move the piece.
4And the way to make your intention clear is to say so. Dec 22, 2014 at 16:43
With some luck, the silently adjusted piece will be an unattacked opponent's piece, or my own piece after I have already moved, before touching the clock; for touching a piece unable to participate in a legal move I might end up penalized for disturbing my opponent (but perhaps not for attempting illegal moves), and I wouldn't lose the freedom of my next move either. Oct 22, 2019 at 16:50
Small kids playing with tournament sized sets on school sized tables topple their kings all the time, because they can hardly reach the middle of the board without touching the tops of the nearest pieces by their elbows. When repositioning the fallen pieces they do so silently because the situation and their intention is already clear enough. A silent correction minimizes the disruption to the opponent.
You should say J'adoube when it's not entirely clear whether the piece has to be repositioned, because being explicit about not making a move minimizes the disruption to the opponent.
Minimizing disruption is not only sportsmanlike behavior, but also a good habit to adopt to prevent disputes.
(With the post-2018 rules, I wouldn't risk skipping on saying J'adoube, not even with my king lying on the floor. But I would also not claim opponent's intent if I'm sure there was none. Have fun.)
As far as I know - yes. If you do not say J'adoube or adjusting before you touch the piece, you have to move it.
3Geurt Gijssen, the former head of the FIDE Rules Commission gave his opinion in a ChessCafe article in the "An Arbiter's Notebook" series (web.archive.org/web/20120510222057/http://www.chesscafe.com/…) regarding a case where a player intended to play Rd1xRd5 but accidentally first picked up his rook on c1 before putting the c1 rook down again and playing Rd1xRd5. Geurt Gijssen ruled that since the intention was clearly RxR picking up the c1R first was an honest mistake and touch-move did not apply. So the former head of the FIDE rules commission disagrees with you.– Brian Towers ♦Dec 22, 2014 at 17:38
3Gijssen's ruling agrees with the spirit of the rule as well, which I believe is to prohibit visualizing moves by "trying them on". It's not intended to penalize simple mistakes or careless bumps.– intx13Jul 13, 2015 at 20:02