Replacing balls off the lawn or within the yard line, when there are already other balls there, has now been simplified and the corners no longer form a special case.

"12b. PRESENCE OF OTHER BALLS. If a ball cannot be replaced in accordance with Law 12(a) [Absence of other balls] because of the presence of:

1. the striker's ball inside the yard-line area; or
2. one or more yard-line balls; or
3. one or more balls outside the yard-line area,

it must be replaced on the yard-line as the striker chooses in contact with any ball that directly or indirectly interferes with its replacement. "

In Example A above the striker has rushed the Blue ball (B) to the position shown, Red (R) is already on the yard line. As the Blue ball lies behind the Red ball it is the striker's option as to whether the Blue ball is replaced on the left or right or the Red ball; it does not have to be replaced on the side nearest where it ended up.

The Black ball (K) in Example B directly interferes with the replacement of Blue on the yard line to the right of Red, consequently the striker has the option of replacing Red to the right of Black. In Example C Black again prevents Blue from being placed in contact on the right of Red, so it can optionally be placed on the yard line in contact with Black.

In the Example (above) the striker has finished his turn with a scatter shot and both Blue and the striker's ball, Yellow, end up in the yard line area. Law 12 goes on to say:

"12 c. INTERFERENCE BY THE STRIKER'S BALL. If the striker is entitled to take croquet, the striker's ball is a ball in hand and an outside agency until it is placed for the croquet stroke and must not interfere with the replacement of a ball under Laws 12(a) or 12(b).
12 d. ORDER OF REPLACEMENT. If two or more balls have to be replaced, the order of replacement is as the striker chooses."

In this example the striker is not taking croquet, hence 12c does not apply and there are six possible replacement configurations of the balls.

A consequence of the change in the replacement rule is that when a ball ends up in a corner where there are already two balls, the striker is no longer obliged to replace that ball on the unoccupied yard line. The figure below indicates this. In the first instance the ball in the corner area can go on either yard line.

The ball does not have to lie within the corner square to be able to be replaced on the 'other' yard line as the remaining two diagrams show.