So what’s a twitch? A twitch is a physical action element involving time. That’s a fancy way of saying “catch the ball, dummy!”
Twitches are anything that forces the player to physically act or respond in some way, and to do so before a timer runs out. It can be “catch the flying ball before it hits the ground”. It can be “place the T-shape in the T-shaped hole before it hits the bottom” (Tetris, anyone?). Now, twitches aren’t two things: they aren’t passive (just having someone throw a ball at you doesn’t count as a twitch) and they aren’t slow (picking up a ball that rests on the ground doesn’t count). Thus action + time = twitch.
Why is this so important?
Because twitching has been the core mechanic of games since before there were games. Sports are based on twitching. Soccer, that’s an easy example: catch the ball, shoot the ball. Rugby. Racing (see turn, twist wheel, press brake pedal). Archery (get the aim-point over the target and release before your arm becomes so tired that you release at the wrong time). You name it.
And any game, any game at all, that has twitch added to it becomes something new. Think about it. Strategy + twitch = RTS. Target shooting + twitch = 3D shooters. Position + twitch = Pong.
Let’s take Chess. Big, slow, stately game, right? Old guys and young prodigies thinking and pondering, that sort of thing. Well, Chess + twitch = Lightning Chess. For those of you who don’t follow Chess terminology: Lightning Chess are timed Chess games where each player has a ludicrously small amount of time to make their moves. Like second. As in singular. It’s the type of game where two people keep alternating moving the pieces and slapping the clock.
Lightning Chess uses the same rules as Chess. It uses the same components as Chess. It plays completely differently. The experience of playing Lightning Chess is not the same as the experience of playing Chess.
In games which are based on twitch, such as RTS games, there’s also a secondary effect: mental focus, the ability to lock out less important elements becomes paramount. There’s a study done on DotA players where the top players’ eyes didn’t shift from their characters for more than milliseconds while very good, but not world class, players looked away for longer periods of time and twitched their eyes to different elements more often. They were distracted by the action on the screen while the top players remained focused on their goals.
(Interestingly their physical reactions, stress, heart rate etc. were the same, meaning that it was the ability to focus and shut out parts of the game that determined if a player would be world class or not.)
So, back to the matter of twitching. If you can add a twitch to a game, and have it become the same game but a different experience, what happens if you take a twitch game and remove the twitch?
You get a model.
That’s right. You can take a twitch game, remove the twitch and have something that you can study, analyze and test at your leisure. This is, in fact, what happens when you design a level. Say that you want a level where the player jumps from pillar to pillar. You design the level without twitch – as you’re sitting there, doing your work, you aren’t timed to it. You can go and get a cup of coffee. You aren’t stressed.
But when you playtest it, you add the twitch and, voila, you get all the benefits of twitch.
Hold on, that’s just plain common sense. What’s the point of this? The point is that when you remove the twitch you can model the twitch actions. You can measure the distances between pillars, raise and lower them, calculate the amount of mistake in timing or angle the player can make and still land properly. You can calculate a percentage and know that if you put the pillar at X distance and the player jumps Y milliseconds early they’ll still make it. You can calibrate the difficulty by math rather than brute force (testing).
It may not be the easiest way to do it (it seldom is, just running through the level is often way more time effective) but it’s a tool. And the next time you end up with a game where players complain that it’s too easy or too hard, take a look at your twitch and see what you can do when you remove it for a while. You might even come up with a completely different genre…