Can you play your numbers in Backgammon in a way to block one of them?
A basic rule of backgammon is that you must play in a way that maximises the use of your pips.

If you have a board that can use both 3 and 6, you must choose such move over any move that only uses 3 or only uses 6.

If you have a board that allows the use of 3 or 6 but not both, you must choose a move that uses only 6 over any move that uses only 3.