Interruptions happen whenever a specimen is within melee distance even if they have attacked, at discretion of DM or out of turn when player reaches melee distance. And case by case basis as listed below.
Interrupting Specimen[]
Any Player passing a Specimen AGI vs Player AGI can interrupt a Specimen within melee range or by lunging if they can reach with one movement even out of turn, but will lose his movement next turn (unlike specimen who does not lose their movement after interrupting). This includes helping grabbed players, players stuggling with a disarm, etc. Players cannot intterupt specimen trying to interrupt.
Interrupting a Husk preparing a shot results in aiming his arm away from his target. On a roll of greater then 3 the interrupting Player can aim at nearby specimen, otherwise the shot goes wide. Husks also get interrupted if on a head, arm or shoulder hits, in this case shot goes wide.
Movement Interruption[]
These can happen even out of turn.
Whenever a Player tries to walk past a Specimen roll less then 3 to see if Player is interrupted. Then roll kind of interruption.
Specimen with Grab or Disarm skill can also try to interrupt by lunging. On Player roll of less then 3 Specimen lunges forward and rolls to see if they suceed to Grab.
Reload Interruption[]
These can happen even out of turn.
If a Player is reloading within melee range of a Specimen, on a roll of less then 4 specimen will intterupt the reloading action, refer to Reloading actions for what happens. Same applies for any specimen (except Siren and Gorefast, which they have no means of interrupting other then attacking) one movement away by lunging but for a roll of less then 3.
Melee Attack Interruptions[]
Melee Attacks cannot be fully interrupted.
Melee Weapons that can Lodge will Lodge at a roll of less then 3 and take one turn to free. If Player has more then one attack, spends rest of the attacks to free the weapon, even if specimen dies and falls.
Only Brute, Scrake and Fleshpound can block melee attacks on a roll of greater then 3. Blocked attacks deal no damage to Specimen and Player loses an attack if weapon has more then one.
Stalker, Crawler and Gorefast may dodge melee attacks on a Speciman AGI vs Player AGI. Recivie no damage and counter attack for 2+D6 on a roll of greater then 3.
Nervousness Interruptions[]
Player without Military Personal and/or Hardend status will have to roll for greater then 3 to see if they are intterupted at the sight of a specimen, their screams out of combat.
During combat they will have to roll for greater then 4 to see if they are interputted whenever something happens that causes Nerve Point Damage regardless of their current NP.
Stalker Intteruptions[]
Unless Players have special equipment to detect them they can pop out of anywhere DM wants them. They can interrupt any action if its the first thing they do when they break their invisibility, even if action is noted as uninterruptable.