Instability | Dark Souls 3 Wiki

Instability is a state in which the player is off-balance and receives 40% extra damage from attacks. The active window for this state is referred to by instability frames. Taking damage from an attack during instability frames results in an instability hit. Instability hits are communicated by a deep, reverberating "thunk" sound effect.

Instability hits are not to be confused with counter hits, which concern damage taken from thrust attacks while in the middle of an attack animation. There is no weapon or item, including the Leo Ring, that increases damage from instability hits.

The player is unstable in the following situations:

• During jumping attacks. Begins when the jumping attack is initiated, ends when the attack hits the ground.
• During running attacks of Great Hammers, Greataxes, and Ultra Greatswords. Very few instability frames are present just before the running attack hits.
• After quickstepping. Quickstep's invincibility frames are followed by instability frames. 
• After being kicked. If you are in the way of an enemy's body after someone knocks them down with a backstab or riposte, it will also act as a kick.
• After being hit by Flame Fan. Being hit with this acts as a kick.
• When you pivot. Pivoting happens if you sprint and suddenly reverse direction. This can be avoided by blocking while sprinting.
• After being parried or guard-broken. If you are not riposted, a normal attack will be an instability hit.
• After trying to parry with fist weapons. If you parry too early, you will take an instability hit.
• After weapon bounce. When attacking in close proximity to a wall, weapons may bounce off.
  • Weapon bounce also occurs when using thrust attacks against players with Perseverance, Iron Flesh, or Stone Flesh active. Light weapons, like daggers and fist weapons, will also bounce in these situations.
• During Gentle Prayer.
• Landing recovery, or when landing on the ground after falling a certain distance. This can be avoided by rolling as soon as you hit the ground.

NPC enemies can also take instability hits, and will do so in more situations than players. Lothric Deserters, for example, are unstable during the start-up of their sword swing. Additionally, unlike players, enemies with medium shields or greatshields will deflect one-handed attacks of many weapons, putting you off-balance. Two-handing your weapon lets you avoid bouncing off their shields.

Many Bosses also take instability hits, usually while they are parried or staggered. Lorian, Elder Prince, for example, can be parried but not riposted, but takes instability hits when attacked after parrying him. Dragonslayer Armour can be staggered after breaking its poise, and will take instability hits while it is down. Other bosses, like Vordt, Dancer and Oceiros can also be staggered this way, and are then open to a critical hit, as well as vulnerable to instability hits.