Unblockable
From Tekkenpedia
An Unblockable is a combat move executed in game. As the name suggests, it is impossible to in any way block the move. However, in the early Tekken games, specifically Tekken and Tekken 2, it was possible to jump unnaturally high, allowing the player to avoid the move. Later on, the key to escaping unblockable moves are sidestepping, backdashing or reversing/parrying. Some unblockables can be evaded simply by ducking.
Usually, every character can perform at least one unblockable move, either by executing it as a stand-alone move, or running 18-22 steps and tackling into a standing or ducking enemy (This feature appeared first in Tekken 2).
The unblockable move appeared first in Tekken. Only a few characters had unblockable moves, such as Yoshimitsu, Nina and Anna Williams, Lee Chaolan, Marshall Law and Jack. With the exception of Jack's stage five wind up punch, which was an instant knockout, the unblockable attacks in the first Tekken game only inflicted 40% worth of damage to a player's health. It was not before Tekken 2 that unblockable moves were more usual and various, and much more common, being not limited to a few selected characters.
Unblockable moves usually require a little bit of time to charge them up, but timed right, they will be very dangerous on hit. Normal average damage of an unblockable hit is around 70-90, but there are weaker attacks that in turn requires less charge time (such as Kunimitsu's body stab dealing a mere 25 damage). One of the strongest unblockable move in the game belong to the Jacks. Their wind-up-punch can, with a clean counter hit and fully wound up, deal 246 damage. Otherwise, it will deal 199 damage, which is an instant knock-out by far. It is second only the Kuma/Panda's "Fatal Winds" dealing a perfect 200. However, while these attacks do provide an instant win if connected, the animation leading up to the attack is far too long for the attack to be of any actual use.
