The 7th edition of The Laws of Association Croquet has recently been released, and is in effect in the USCA. Here are some of the changes most likely to affect play:

• Striking period redefined: the striking period now matches that of Golf Croquet. During the striking period, any contact with a ball other than the striker’s ball is a fault. If the striker is attempting a critical stroke and has not marked the striker’s ball, any contact with that ball during the striking period constitutes a stroke. However, if the stroke is not critical and/or the ball is properly marked, accidental contact with the striker’s ball is forgiven if the swing is stopped before contacting the ball a second time. These changes are of particular concern to players who use the “casting” style.
• Causing court damage or striking with a part of the mallet other than the end face is a fault when:
  ..- attempting a hampered stroke
  ..- attempting to make the striker’s ball jump
  ..- the striker’s ball is part of a group
• Referee awarding a fault post-facto: if neither player called a referee to adjudicate a stroke before it was played, the opponent may appeal to a referee after the stroke is played; the referee may award a fault if satisfied, based on evidence other than that provided solely by the opponent, that a fault has occurred.
• Multiple errors and interferences: interferences are now included in the compound-error law.
• Playing or declaring a stroke before the previous stroke ends: as long as the striker’s ball is at rest, you are no longer required to wait for the previous stroke to end before playing or declaring your next stroke (unless there is any chance that doing so could affect either stroke). In some circumstances this could allow you to finish your current turn before the extension period begins.
• Time wasting: the new Law 63.5 outlines the procedure and some possible remedies. Step 1 is that a player who believes that the opponent is wasting time must first inform the opponent. If this does not solve the problem, the player may appeal to a referee. The referee will observe the game and decide whether or not action is called for.

For additional information refer to the WCF's AC Laws page.