You’d be forgiven for thinking that every move and every system you’ve ever enjoyed in a video game has been planned to the last meticulous detail. But hey, sometimes a thought just comes to you, and the results stand the test of time.

Here, for example, is a wonderful old video that’s been dug out of the archives by Mortal Kombat co–creator Ed Boon, ahead of the series’ 30th anniversary next year. It shows a ton of behind-the-scenes footage from the original game’s creation—the kind of stuff Boon has posted on Twitter before—but in this case it goes beyond just looking at the actors and shows some on-the-fly development in action.

This is wild. Scorpion’s spear throw, one of the most iconic moves in fighting game history, was just…thought up on the spot, with actor Daniel Pesina right there, ready to workshop the whole thing live. Boon elaborates on the footage in some follow-up tweets, explaining stuff like how important it was that the actor limit the number of frames used to capture the move, and how parts of the throw ended up using “recycled” animations.

We certainly did a ton of prep for our video shoots, but some ideas came to us while filming. With Scorpion’s spear, it started with “You know what would be a cool ass move?”. From there you can be a fly on the wall and see us working through the details.

One of those details was how fast Scorpion threw the spear, which had to be quick so he could catch opponents by surprise. This meant keeping the animation simple & very few frames. We also wanted the spear to pass over a ducking opponent, so we kept it at chest height.

We were so tight on memory, that we didn’t even capture any motions for the victim reactions. Instead we borrowed from their existing animation frames. You can hear us talk about reusing one of the victim’s “knockdown” animations when they initially get hit by the spear.

We also borrowed the victim’s “fatality dizzy” frames to show they were stunned after being pulled in. Reusing existing animations was one of the many tricks we used to save memory, which was so much more limited in 1991.

A few things make me laugh watching this so many years later. Try counting how many times you see my arm reach out from the right side, trying to (ninja) mime the move. Also hearing @therealsaibot describe how he wants to make the rope like a snake by saying “shh shh”.

Also… did you notice how young Ed Boon really likes to use the word “WAH” to describe things? WTF?

Finally, while there was SO MUCH more involved with us creating this classic move (fx, sounds) it’s still kool to see the germ of an idea that eventually became so synonymous with Mortal Kombat, and duplicated SO MANY TIMES in future games, movies, tv, animation & comics!

I know “eureka” moments must happen all the time, maybe even just like this, but fans getting to see them in action so many years later is just very, very cool.