Wavedashing is a movement option that is available in the fighting game Rivals of Aether, that comes from Super Smash Bros. Melee. It is performed by short hopping (performing a small jump) and then air dodging (performing a defensive attack in the air) into the ground. Wavedashing is useful for improving your gameplay, as it is a better movement option than rolling, running or walking, since it is both faster and allows different actions to be performed out of wavedash (immediately after the wavedash is performed).

Read more about the uses of wavedashing in Smash Bros. Melee here: http://www.ssbwiki.com/wavedash

Step 1: What You Need

Of course, to wavedash, you'll need Rivals of Aether. You can buy Rivals for PC on Steam (http://store.steampowered.com ) for $15. It is in early access stage right now.
If you have an XBox One, you can also use that to play Rivals.
You can also practice wavedashing in Super Smash Bros. Melee if you have the game, since wavedashing is the same in that game.
Next, you'll need a controller.
There are several controller options:
1. Keyboard (PC Edition): This is arguably the hardest way to play Rivals of Aether, but it comes with the game.
2. XBox 360 Controller (PC): If you have a 360 controller, you can use it with Rivals as well. Go to options, and change your controller setting to XINPUT.
3. XBox One Controller (X1 Edition): This is pretty straightforward.
4. Gamecube Controller (PC Edition): If you have a Wii U PC Adapter, then you can use a Gamecube controller by connecting it to your PC, then changing your controller setting to DINPUT in options. Also compatible with Smash Bros. Melee. I find that this is the easiest controller to wavedash with, and it is what I use currently.

Try each controller for yourself.

Step 2: Short Hop.

Press the jump button very briefly to short hop.
In the case of the Gamecube controller that has not been re-mapped, press X or Y very lightly and quickly.
Your in-game character should perform a very short jump.
Practice this until you can do it well.

If you hold it too long, then you will perform a full hop (it should be easy to tell the difference between the two). Make sure you are not full hopping, since it is impossible to wavedash with a full hop.

Step 3: Air Dodge Directionally.

Now, while you are in the air, press your SHIELD button (by default, this is L or R) and hold your analog stick downwards and the direction you want to move in (if I wanted to wavedash to the right, my analog stick would be DOWN AND TO THE RIGHT). Your character will slide downwards and towards the direction you held very quickly.
Since there is a very brief time frame that you are in the air after short hopping, it may take a while to get the hang of wavedashing.
If you are doing it correctly, a small "hoosh" noise will be made as you land. It should not even look like you have even left the ground.

Step 4: Practice and Tips.

Repeat the wavedash (short hop -> directional airdodge) until you are fully certain that you can perform it consistently.

If you did not before, you can read up on the uses of wavedashing in Smash Bros. Melee to help you understand your Rivals gameplay better, since most tips also apply to Rivals: http://www.ssbwiki.com/wavedash

Keep in mind you can wavedash backwards, but you character will usually turn around after that.
Also remember that different characters have different wavedash lengths. Longer wavedashes are usually better, but a short wavedash does not make a character bad. Go experiment.

Some manuevers with wavedashing:
Wavedashing forwards followed by an attack
Wavedashing backwards to avoid an attack, then wavedashing back in
Wavedashing to the edge of a platform to get to the side without falling off