There’s a couple of ways to get in a damage-boosting 'Critical Attack' on an enemy. Firstly there’s the Guard Break , a move that allows you to instantly stunlock your opponent for a few seconds giving you the opportunity to go in for the critical hit. The second is known as the backstab (a move that was in the original Dark Souls). Let’s take a closer look at both moves in more detail.
If you spot a target holding their shield up; you can get right up to them and press Up + Normal Attack together to trigger an animation that bashes your opponent’s shield away from them. This generates the stunlock.
A great area to practice this move properly is in the Forest of the Fallen (on the wall that leads to the bonfire shortcut) as there are a few Hollow Soldiers that carry shields (and they’re less likely to kill you super quick).
Note: You’ll perform the guard break animation faster if you do it bare handed (i.e. without a weapon or shield in your right hand ). Swinging your right-arm with a weapon in it takes fractionally more time to perform, so switching a weapon out, performing the guard break and then switching the weapon back will gain you more success. You can practice this by using a dagger instead of bare-handed so you at least still have a weapon to use if you’re not quick at switching weapons fast.
If you circle behind an opponent you will have the opportunity to smack your weapon into their back, triggering a unique animation sequence that results in an often cool looking and more painful attack on your target (of particular note is the Mace’s backstab animation - ouch)!
Personally, we’ve found we could nearly nail this every time when we positioned ourselves just to the left of the character’s spine. When we stood directly behind an opponent we found that this didn’t always work. But when we stepped left slightly it worked more often than it failed.
Note: There’s a ring hidden in the game (check further into our guide for the exact details) that prevents enemies from backstabbing you. If you play a lot of PvP then it’s worth checking out how well it works for you (as you get backstabbed a lot less in PvE battles).