The purpose of this page is to document all of the known tricks
of NES Double Dragon 2: The Revenge, so far.
Because of the nature of this site, we concentrate here on tricks
that are nearly difficult to play in real play, but are useful
in the making of tool-assisted speedruns. For most of the tricks,
a [Glossary|frame advance] feature in an emulator is a definite must-have.
!! Double Flying Knee glitch
Typically if the two brothers do a flying knee at the same time they will either fly in opposite directions, or one will always hit the other first. Under certain circumstances they can hit each other and fly in the same direction. This possibility opens up a lot of possible shortcuts.
To get this to work the brothers must be moving in the same direction. They also must be at the same height (on 3D floors). In addition RAM addresses 0x0489 and 0x048C must be low values. If they are high, the trick does not work. These values increase each time the brothers do damage to each other. The flying knee does the most to increase it. Therefore, the double flying knee glitch can not be done twice in a row.
!! Double Jump Kick
Works just like the flying knee but with jump kicks. Jump kicks don't propel them nearly as far but can be useful in certain situations.
In the video example the double jump kick happens just before the knee but is off screen. (Unfortunately this is the only example in the published movie)
!! L+R Flying Knee Glitch
By pressing left + right at the same time while performing a flying knee, the player will jump straight in the air while doing the knee (instead of to one direction or the other). This has many time saving uses.
If doing the glitch on "3D" terrain, the player will land on the top of the 3D space. Surprisingly this has little TAS value.
!! Teleportation Glitch
This is derived from the L+R Flying Knee glitch but specifically using it in the enemy scene of stage 6. Go to the left of the platform and do a L+R knee. The player will land on an imaginary platform for 1 frame then fall down (note: it is not possible to jump from this platform). Now anytime the L+R is used on the platform or to the right it, the player will teleport to the left of it.
This glitch does not have value in a 2-player TAS but can save time for a 1-player version as demonstrated [http://dehacked.2y.net/microstorage.php/info/1957005972/Double%20Dragon%202%20-%20The%20Revenge.fcm|here].
!! Enemy Teleportation Glitch
This is another application of the L+R Flying Knee glitch but applied to Stage 5 before the train. Using the L+R glitch here causes the enemies to walk to the left of the screen, jump up and then teleport off screen! This is (currently) not advantageous in a speedrun.
!! Level 6 Shortcut
With frame perfect timing and a good Y subpixel value, it is possible to jump up to the ledge of the door from the 2nd disappearing platform.
!! Damage Boost Shortcuts
There is not as many of these as it would first appear. When you hyper uppercut or spin kick a player he goes flying into the air. At first it seems this would be easy to use to knock them onto high ledges.
However, the game keeps track of what ledges a player __could__ land on. Then game doesn't allow any boosting up to ledges that couldn't normally be jumped to. However, damage boosting is still useful for horizontal boosting. This typically involves landing on a ledge quickly that normally would take several jumps.
!! RAM Addresses
* 0x0489, 0x048C - Related to the double flying knee glitch
* 0x0420, 0x0421 - Enemy Health
! Damage Table
|Kick - Knockdown|6|
|Hair grab + knee|5|
|Hair grab + elbow bash|6|
|Hair grab + throw|12|
|Hair grab + kick|14|