AuraSeer said:To set against a charge, you use the ready action. This works just like readying any other attack. If an opponent charges you while you are ready, you make a single attack roll as soon as he enters your reach. In this special case of a set piercing weapon, a hit deals double damage.
Now, suppose you did this and an enemy simply walked up to you and attacked normally, instead of charging. Would you still get to attack when he entered your reach (without the double damage, of course)? Or would you simply lose your action?