OBSTRUCTION:
Unlike footballers, hockey players aren't allowed to deliberately shield the ball from the opposition.

A player is not allowed to

• back into an opponent
• physically interfere with the stick or body of an opponent
• shield the ball from a legitimate tackle with their stick or any part of their body
• run in front of or block an opponent to stop them legitimately playing or attempting to play the ball (this is third party or shadow obstruction).

This is to make sure all players have an equal chance to gain control of the ball.

However, a stationary player receiving the ball is permitted to face in any direction.

And a player with the ball is permitted to move off with it in any direction (except into an opponent) - so as long as you keep moving, you should not be penalised for obstruction.

STICK TACKLING:
You can't hit, hook or hold an opponent's stick with your stick. You aren't permitted to play the ball with the back of the stick (including the shaft) either.

The rules state that players must not tackle unless in a position to play the ball without bodily contact.

FEET:
Only goalkeepers are allowed to use their feet in hockey. Field players are not allowed to use their feet, or any other part of their body, to control the ball or to gain an advantage.

If no advantage is gained, the umpire will allow play to continue.

OFFSIDE:
There is no such thing as offside in hockey.

DANGEROUS PLAY:
Players on the field must hold their stick and not use it in a dangerous way - for instance lifting it over the heads of others.

Players must not play the ball with any part of the stick when the ball is above shoulder height (except: defenders are allowed to raise the stick to any height if they are attempting to stop or deflect a shot at goal ).

Players must not play the ball dangerously or in a way which leads to dangerous play - the umpire deems it to be dangerous if it causes legitimate evasive action by players.

Players must not intentionally raise the ball from a hit except for a shot at goal.

If it is raised unintentionally, the umpire will allow play to continue unless it is deemed dangerous.

Players are permitted to raise the ball with a flick or scoop provided it is not dangerous - if it is within five metres of an opponent it will be considered dangerous.

Players must not approach within five metres of an opponent receiving a falling raised ball until it has been received, controlled and is on the ground.

CONDUCT:
Players must not force an opponent into offending unintentionally.

Playing the ball clearly and intentionally into any part of an opponent's body may be penalised as an attempt to manufacture an offence.

Forcing an opponent to obstruct (often emphasised by running into an opponent or by waving the stick) must also be penalised.

Information provided by the BBC, please see there hockey pages for more information.