Whenever a player or monster takes damage, there is a chance they will be stunned. A stun interrupts whatever that creature was doing while a brief animation is played.
Mechanics of stun[ | ]
The chance to stun is based off the damage done in a single hit compared to the target's maximum life. The default length of stuns is 350ms.
The duration of stuns can be altered by increased Block and Stun Recovery, increased Stun Duration on enemies, increased Stun Duration with Two Handed Melee Weapons on enemies and similar modifiers.
Whether or not a stun occurs can be calculated using the following formula:
stun_chance = 200 * damage / defender_effective_max_life
Where defender_effective_max_life is what the maximum life of the creature would be in a single-player map. Increases to monster life from a party of more than one player do not affect defender_effective_max_life.
For a player with Chaos Inoculation, their defender_effective_max_life is whatever their maximum life would be if they did not have Chaos Inoculation.
If the chance to stun would be less than or equal to 25%, it is ignored, so you need to deal more than 12.5% of effective maximum life to have a chance to stun.
Stun threshold[ | ]
Reduced stun threshold modifiers reduce the value of defender_effective_max_life. For example, 25% reduced Enemy Stun Threshold means the enemy will be treated as if their defender_effective_max_life is only 75% as much as it actually is, increasing the chance that the enemy will be stunned.
There are diminishing returns affecting stun threshold reduction. When the total Stun Threshold Reduction would be over 75%, it is instead treated as being:
75 + ( Stun Threshold Reduction - 75) * 25 / ( Stun Threshold Reduction -50 )
For example, if a player has a total of 110% reduced Enemy Stun Threshold from gear and skills, the actual value that gets used would be:
- 75 + ( 110 - 75 ) * 25 / ( 110 - 50 )
- 75 + 35 * 25 / 60
- 75 + 35 * 0.42
- 75 + 14.6 = 89.6% reduced Enemy Stun Threshold
| Reduced Enemy Stun Threshold | Effective Reduced Enemy Stun Threshold | Percentage of Life a hit needs to deal to have 100% stun chance |
|---|---|---|
| 0% | 0% | 50% |
| 5% | 5% | 47.5% |
| 10% | 10% | 45% |
| 15% | 15% | 42.5% |
| 20% | 20% | 40% |
| 25% | 25% | 37.5% |
| 30% | 30% | 35% |
| 35% | 35% | 32.5% |
| 40% | 40% | 30% |
| 45% | 45% | 27.5% |
| 50% | 50% | 25% |
| 55% | 55% | 22.5% |
| 60% | 60% | 20% |
| 65% | 65% | 17.5% |
| 70% | 70% | 15% |
| 75% | 75% | 12.5% |
| 80% | 79.2% | 10.4% |
| 85% | 82.1% | 9% |
| 90% | 84.4% | 7.8% |
| 95% | 86.1% | 7% |
| 100% | 87.5% | 6.25% |
| 110% | 89.6% | 5.2% |
| 120% | 91.1% | 4.5% |
| 130% | 92.2% | 3.9% |
| 140% | 93.1% | 3.5% |
| 150% | 93.8% | 3.1% |
Energy shield[ | ]
As long as a creature has greater than 0 Energy Shield, it has a 50% chance to avoid stun. This is calculated independently of the creature's chance to be stunned. First the chance to stun is calculated as normal, and if the stun check succeeds and would cause a stun, there is then a 50% chance that the stun can be avoided.