To enter a checker from the bar, you roll the dice and bring it into your opponent's home board on a point matching one of the numbers you rolled. That entry point must be open, meaning it is not blocked by two or more enemy checkers. If both numbers you rolled correspond to blocked points, you cannot enter and forfeit the whole turn. You must get every checker off the bar before you may move any other checker. This is why building a strong home board full of made points is so valuable: it can trap your opponent's checkers on the bar and cost them many turns.