Additional Rules from the Rulebook
You draw cards and add them to your hand before putting one back. The card you put on top of your deck can be any card in your new hand and doesn't have to be one of the 3 you just drew.
The Secret History of Courtyard
In an article on Board Game Geek, Donald X. Vaccarino commented on the development of Courtyard:
- Almost all of the Dominion cards, from the main set and all of the hypothetical expansions, were designed by me. Which is just the way I like it. This one was not though. In the early days of Dominion, one of my friends printed/cut/sleeved his own copy, and along the way he added like a dozen cards. I played with them and liked a few that I hadn't thought of yet, and well this is one of them. I had previously tried "+1 Action, +2 Cards, put two cards from your hand on top of your deck," but nixed that for causing too much AP. This card does cause a little AP, but is much better.