All three of those types of discounts, plus occaisionally codes are offred for pretty much every type of room at WDW, except suites.
There is aplace here on teh DIS where you can view various current codes and promotions, sorry I do'nt have the link but I'm ssomeone will post it for you. Best bet is to be flexible with your travel plans and dates, and keep checking.
If you are trying to get a discount during a peak or holiday period your chances will be much lower.
If you're willing to take a chance, especially in a lower travel time, you can also book a regular room at the YC and try to upgrade at checkin, sometimes the cost is lower than it would be by booking it in advance. Of course there are no guarantees.
Anne