Crouching is performed by holding 
. High attacks and grabs will always whiff crouching players. However, a lot of characters lack good attacks or strings from a crouching position, so being able to launch or hard knockdown an opponent from a crouching position (either through a single move or a string) is considered a very valuable asset to the character.
Dashing is performed by double tapping a direction. This is the fastest way to move in the game, however dashing has a fair bit of endlag before you can move again, and it has a short cooldown before another dash can be attempted after this endlag. However, both of these downsides can be completely negated with some tricks.
Dash Canceling
Pressing to crouch will cancel the momentum of the dash, but it will cut any endlag as well as reset your dash timer, allowing you to immediately dash again once you release crouch. If used near the end of the dash once your character starts slowing down, very lightly pressing crouch and then inputting another dash allows you to greatly speed up your momevement.
R-Canceling
The R1 and R2 buttons are not bound to any action, and do nothing in game. However, they have a weird quirk that when pressed interrupts how the game checks to see which inputs you've pressed recently. This means that you can perform a dash, press either R button, and then immediately halt the dash to begin attacking with a normal instead of a dash attack. This allows you to extend the range of normal dramatically, rewarding good spacing with devastating punishes. R-Canceling is not necessary for command moves that use one or more direction inputs.
Counters are a defensive tool that can be enabled or disabled in the options menu. Every character has access to two different kinds of counters, which can be used in two different ways - parries and combo breakers.
Pressing 
will parry 
and 
attacks, and 
will parry 
attacks.
When a successful counter is performed, it executes a universal move that deals 15 damage and causes a hard knockdown to any opponent caught in it's large hitbox.
Counters last 7f, however the game only checks to see if you're currently in this 7f window before beginning another counter, which means with proper timing you can constantly be in a countering state, even if your animation doesn't portray you doing so. A common camping tactic is to hold crouch while constantly switching between countering high and low.
Parrying
Parrying is performed by pressing either counter input when you're not in an attack animation or in or hitstun, and can be performed while crouching. Parrying will perform an animation where your character reels back, but this same animation plays whether you're parrying high or low, allowing you to mask which parry you're using. You are unable to move, attack, or block during the parry animation.
Breakers
Counter inputs can be performed even when you're in hitstun and actively being attacked by another player. A combo string can be countered out of when the string switches from a or attack to a attack, or vice versa. Pressing counters the change to a or , and counters a change to a attack.
This mechanic keeps (almost) all of the 0-to-death combos characters possess in check, as most of them contain several opportunities for victims to counter out of them. This also adds a lot of value to characters that possess several combo paths from their buttons, allowing them mix their opponent up of when to counter high or low.
The combo strings present on each of the character pages will contain either a " 
" or a " 
" to denote that your opponent can either high or low counter out of the combo, respectively. For example, this Tormentor string has two opportunities to counter out of it after the first hit:
Strings that possess no ways to counter out of them after the first hit are considered "safer", and thusly more desirable.
