When is a penalty corner awarded?

FIH Rule 12.3: a penalty corner is awarded:

1. for an offence by a defender in the circle that does not prevent the probable scoring of a goal;
2. for an intentional offence in the circle by a defender against an opponent who does not have possession of the ball or an opportunity to play it;
3. for an intentional offence by a defender outside the circle but inside their own 23-metre area;
4. for a defender intentionally playing the ball over the back-line. Goalkeepers may deflect the ball in any direction, including over the back-line, with stick, protective equipment or body;
5. when the ball lodges in a player's clothing or equipment in the circle they're defending.

Compare:

• An unintentional offence by a defender outside the circle but inside their 23-metre area is a free hit to the attack (12.2 c).
• An offence in the circle that prevents a probable goal, or an intentional offence against a player who has the ball or a chance to play it, is a penalty stroke (12.4).
• An unintentional ball over the back-line by a defender, or a goalkeeper's deflection, restarts on the 23-metre line in line with where it went out (7.4 b).

FIH asks umpires not to hesitate to award a corner when it's clear a defender played the ball over the back-line on purpose.