Stabbing is a standard technique in third-person action games, so you might have been a little surprised when you snuck behind your first enemy Nioh 2 and couldn't make the move. While Nioh 2 gets a stab in the back, it's not a default technique, and rather, it's something you'll need to unlock through the skill trees in the game.
If you want to use the dagger technique in Nioh 2, you will need to work on your Ninja skills, as can be found in the Ninja skill tree.
The Sneak Attack skill which allows you to stab in the back can be unlocked with a skill point, but only after unlocking the Tiger-running skill first. Once you've unlocked the Sneak Attack skill, you can stab enemies by hitting Triangle behind an enemy who is unaware of your presence.
How to get Ninja Skill Points
To get Ninja Skill Points in Nioh 2, you can use an item called Ninja Lock. This can be obtained by completed missions, like a drop of certain enemies and bosses, or it can be looted at random throughout the game. You can also use Ninja items that you collect around the levels, and you will earn points Ninja familiarity and skill using them.
If you need help with other aspects of Nioh 2, we have guides on how to cleanse a shrine, understand how to effectively Burst Counter, and how to beat Gozuki. We can even tell you about those little round ghost cats that you might have seen in different places.