Allow and Deny

Allow and deny blocks can be used to create restricted building areas or areas where users can build. They are exclusive to and.

Obtaining
The allow and deny blocks are not available in the Creative inventory. It can either be obtained by using the pick block control, or by using various commands, such as,  ,  ,or.

Usage
When placed, allow blocks let users without world builder status place or destroy blocks in the area above them, while deny blocks prohibit users from placing or destroying blocks in the area above them. Neither block affects the area below them. If two allow or deny blocks are placed on top of one another, the block that is highest takes precedence. If an allow block is placed somewhere with a deny block below it, the space between the two blocks is protected while the space above the allow block still permit users to place and destroy blocks. The inverse is also true.

Both blocks are extremely resistant to explosions, even though they can still be destroyed by the ender dragon.

Users with world builder status are able to place and destroy blocks regardless of where any allow or deny blocks are placed.