PvP Mechanics
The mechanics you see in PvP are the same as the ones you will find in PvE. However, they are much more important to know about if you want to step into the arena. In terms of skills, PvE focuses on high damage skills. PvP, in contrast, will focus on utility just as much as damage.
Mechanics
Lift : Skills can launch you into the air (some skills have higher lift than others)
Knock : Skills can knock you to the ground where you are unable to get up for a period of time ; to escape being knocked, you can roll or use your wake up attack.
Stagger : Skills that leave you staggered, unable to move. You can use power evades or crisis evades to escape. Any hit following a stagger will knock you down.
Stun : Skills that stun leave you unable to move with stars above your head. You slowly fall to the floor. Power evades cannot escape a stun.
(Wall) Bounce : You can bounce an enemy off the wall for more combos.
Super Armor (aka SA) : Allows you to continue casting despite being hit. Different skills have different Super Armor and Super Armor break values. Having a higher Super Armor value on the skill you are casting than the Super Armor break value of your opponent will keep you standing and casting. Male classes tend to have higher Super Armor. Super Armor and SA break values for different skills have been recorded and neatly organized on this chart created by Radeyz, Azure, Mango and Miya of DN EU. (Source: DN NA Forums SA Spreadsheet thread, Spreadsheet by DN EU members)
iFrames : Invincibility frames make you unable to be hit (invincible) for short periods of time. Not all skills have an iframe, but the ones that do are infinitely useful for evading your opponent's attacks. Your evasion/tumble skill has an iframe.
Evasions
Every class has at least two evasion skills. These all have iframes that let you escape or respond to incoming attacks.
Tumble/Evade : Your basic evasion skill. Every class has one. Double click in a direction, or more commonly, shift + click a direction.
Aerial Evasion (aka AE) : Allows you to escape if you are hit by a lift skill or are otherwise tossed into the air. Space after being hit into the air.
Power Evade : Allows you to escape while being attacked or on the ground/knocked. Not all classes have this (ex. Tinkerer and Cleric).
Crisis Evade : Allows you to escape while being attacked, but not under stagger. Tinkerers and Clerics have this (ex. Engineer's flashbang, Alchemist's Sleep Escape, Priest's Vengeance Wave).
Pop Up / Wake Up Attack : Allows you to pop up from the floor, attacking an enemy close to you. Has a short range. Every class has this.
Other terms for PvP
These are PvP Technique terms (as opposed to mechanic terms) that you may come across. Good PvPers will know not only what these terms mean, but also how to execute these techniques.
Catch & Recatch : After an evade has been used to escape your combo, you can catch or recatch them again in a combo, effectively wasting their evade and forcing them to wait for their evades to go off cooldown. Catching your opponent is often also called "burning" their evade.
Bait : Using a skill that prompts your opponent to use their evade is baiting their evade. It often is followed up by a combo, because they can no longer evade you.
Combo : A chain of skills used in succession that prevents the opponent from escaping or countering. When you fail to continue your combo (your opponent successfully escapes), it is often called "dropping" your combo.
Infinite Combo : An infinite combo, which is sometimes a wall combo, is a combo that does not end and catches very well. Can go on infinitely. Often refers to never ending combos consisting of low level skills. These tend not to do a lot of damage but over time can shave off a hefty amount of HP.
Wall Combo : Wall combos utilize walls to bounce off of to continue combos. Often uses low level skills in them or skills with low cooldown.
Reaction & Prediction : Most players play 1 of 3 ways : play by Reaction, Prediction, or both. Reacting quickly (and efficiently) to an opponent's attack is fantastic for responding to various situations, and getting yourself out of sticky ones. Being able to predict what the opponent does next is a great advantage for any PvPer. The best PvPers will have great reaction times and good reaction skills, paired with honed prediction skills. These skills help players catch and recatch opponents well, and can keep a combo going after burning evades.
Knock : Skills can knock you to the ground where you are unable to get up for a period of time ; to escape being knocked, you can roll or use your wake up attack.
Stagger : Skills that leave you staggered, unable to move. You can use power evades or crisis evades to escape. Any hit following a stagger will knock you down.
Stun : Skills that stun leave you unable to move with stars above your head. You slowly fall to the floor. Power evades cannot escape a stun.
(Wall) Bounce : You can bounce an enemy off the wall for more combos.
Super Armor (aka SA) : Allows you to continue casting despite being hit. Different skills have different Super Armor and Super Armor break values. Having a higher Super Armor value on the skill you are casting than the Super Armor break value of your opponent will keep you standing and casting. Male classes tend to have higher Super Armor. Super Armor and SA break values for different skills have been recorded and neatly organized on this chart created by Radeyz, Azure, Mango and Miya of DN EU. (Source: DN NA Forums SA Spreadsheet thread, Spreadsheet by DN EU members)
iFrames : Invincibility frames make you unable to be hit (invincible) for short periods of time. Not all skills have an iframe, but the ones that do are infinitely useful for evading your opponent's attacks. Your evasion/tumble skill has an iframe.
Evasions
Every class has at least two evasion skills. These all have iframes that let you escape or respond to incoming attacks.
Tumble/Evade : Your basic evasion skill. Every class has one. Double click in a direction, or more commonly, shift + click a direction.
Aerial Evasion (aka AE) : Allows you to escape if you are hit by a lift skill or are otherwise tossed into the air. Space after being hit into the air.
Power Evade : Allows you to escape while being attacked or on the ground/knocked. Not all classes have this (ex. Tinkerer and Cleric).
Crisis Evade : Allows you to escape while being attacked, but not under stagger. Tinkerers and Clerics have this (ex. Engineer's flashbang, Alchemist's Sleep Escape, Priest's Vengeance Wave).
Pop Up / Wake Up Attack : Allows you to pop up from the floor, attacking an enemy close to you. Has a short range. Every class has this.
Other terms for PvP
These are PvP Technique terms (as opposed to mechanic terms) that you may come across. Good PvPers will know not only what these terms mean, but also how to execute these techniques.
Catch & Recatch : After an evade has been used to escape your combo, you can catch or recatch them again in a combo, effectively wasting their evade and forcing them to wait for their evades to go off cooldown. Catching your opponent is often also called "burning" their evade.
Bait : Using a skill that prompts your opponent to use their evade is baiting their evade. It often is followed up by a combo, because they can no longer evade you.
Combo : A chain of skills used in succession that prevents the opponent from escaping or countering. When you fail to continue your combo (your opponent successfully escapes), it is often called "dropping" your combo.
Infinite Combo : An infinite combo, which is sometimes a wall combo, is a combo that does not end and catches very well. Can go on infinitely. Often refers to never ending combos consisting of low level skills. These tend not to do a lot of damage but over time can shave off a hefty amount of HP.
Wall Combo : Wall combos utilize walls to bounce off of to continue combos. Often uses low level skills in them or skills with low cooldown.
Reaction & Prediction : Most players play 1 of 3 ways : play by Reaction, Prediction, or both. Reacting quickly (and efficiently) to an opponent's attack is fantastic for responding to various situations, and getting yourself out of sticky ones. Being able to predict what the opponent does next is a great advantage for any PvPer. The best PvPers will have great reaction times and good reaction skills, paired with honed prediction skills. These skills help players catch and recatch opponents well, and can keep a combo going after burning evades.
End Note
If you are ready for the challenge and excitement that PvP offers, I suggest you keep reading... or get in game and give it a shot! I remind you that DN PvP is thorough and complicated. It requires a lot of skill, and thus patience and excitement to learn gather this skill through experience. If you are unaccustomed to this kind of fast, intense Player vs Player combat, it might take you a while to learn. Losses are inevitable as a new player, so don't get too upset, be optimistic, and do your best!