Headshot Protection is the probability of ones chance of surviving a headshot when wearing certain gear.
How it Works
Myth: Headshot Protection is measured by the chance of survivng a headshot, for example a player wearing a MICH helmet, which offers a 20% headshot protection, would survive an average of 20 times for every 100 times they are shot in the head.
Fact: PumpAction recently clarified how headshot protection actually works. The percentage represents how much damage will be taken off the headshot damage total. As most guns will result in rather high headshot damage, there is still VERY little chance one can survive a Headshot even if they have the Ballistic Helmet, the alleged "most headshot protective item in the game". However at far-distant ranges, damage drop-off may lower the total headshot damage enough that the headshot protection may be able to save the wearer. This would only prove to be effective if the wearer's playstyle incorporates excessive camping as faster player movements would allow the user to dodge such shots. In conclusion, buy some Gear that give Armor Points or Speed, because they actually create a noticeable change to your character.
The term headshot protection is also quite misleading as the term headshot damage reduction is much more appropriate
Interestingly, looking at the damage check at the bottom right corner upon death will reveal that the amount of damage taken compared to helmet on and no helmet by the same weapon is quite different. For example, when shot in the head by a L96A1 one with no helmet will take 999 damage, while a person wearing the MICH will take around 700 damage.
Limitations and Tradeoffs
Headshot protection has its limits, as it is overridden when you're shot by a sniper rifle of any kind, as well as the extremely powerful Desert Eagle and Anaconda sidearms. You didn't think that when you survive a headshot you can get away uninjured did you? Well, you're dead wrong, for those that did survive a headshot they would take a large amount of damage to the head, usually remaining with single digit HP.