"Knock Down" is a Special Combat Effect.
Special Combat Effect
Various special attacks and other effects can cause a Model to receive a Special Combat Effect. There are four of those:
- "Knock Down" (icon: banana peel). If a Model suffers at least one Hit from an attack with a "Knock Down" effect, then the target is Knocked Down. Mark this by laying its miniature on its side. The target must spend its next Move Action to stand up before it can attack anything.
- "Push Back". If a Model suffers a Push Back effect, the player controlling it moves it into one of the three Adjacent Squares that are located away from the direction of the attacker. This doesn't trigger Free Attacks. If the Model can't move back because of walls or other thing that block movement, it instead suffers the "Stun" effect. If an Alien Unit suffers a Push Back effect, all the Models in the Alien Unit are pushed back one Square.
- "Shaken". A Model or Alien Unit that becomes "Shaken" must move an immediate Move Action to move as far away as it can, within its movement range, from whatever caused the "Shaken" effect. If the Model or Alien Unit suffered the "Shaken" effect on their Turn, and they have any Actions left, they make take them as usual, except that they cannot make an attack against whatever caused the "Shaken" effect.
- "Stun" (icon: three stars). The effect of Stun is similar to Knock Down, except that the Stunned Model or Alien Unit must spend an Interact Action to recover, and that it cannot defend against Melee attacks as long as it is Stunned.
Note: the difference between "Stun" and "Knock Down" may seem tiny, but it becomes slightly more noticable due to the general Action rule that a Model or Alien Unit can't perform two actions of the same type on its Turn.