A couple of weeks ago, I watched the opening cinematic for Left 4 Dead, and I was really impressed how much it revealed about the game's mechanics and enemies. This is an excellent example of a game teaching players what they need to know.
The trailer teaches the player how to play the game, or in several cases, how not to. I'd been following the game for awhile when I saw the trailer, but assuming I knew nothing about the game at all, here's what I could learn by watching that video:
- (0:37) There's an enemy who cries, that you can hear from far away. If you shine a light on her, she'll go crazy with rage. Try to avoid her.
- (1:41) There's an enemy who can shoot out its tongue, disabling survivors and pulling them in. Kill this enemy before it manages to reel in your friends. This enemy seems to be most effective at attacking when everyone is busy fighting or otherwise distracted. It would be very good at picking off a single survivor.
- (2:00) Zombies are attracted to the red light on grenades.
- (2:21) There's an enemy who can run on walls and climb on things easily, and make huge lunges. He can knock down your friends and start mauling them, but if you get there in time you can save your friend.
- (2:34) Car alarms can be set off, and seem to attract huge waves of zombies in a way that normal noise does not.
- (2:58) There's a huge enemy that can take tons and tons of damage, and seems to disregard any collateral damage that it may do to the lesser zombies. He seems to focus on whatever survivor is hurting him the most.
After seeing this cinematic, a player can enter the game already armed with some data about how to play the game. But only because Valve made sure that the information they were giving the players was consistent with the actual game mechanics.
Imagine starting the game, being surrounded by enemies, and deciding to spend one of your precious grenades. How angry and frustrated would you feel if the zombies didn't follow the grenade like they did in the video, and you died? Or if the Witch aggroed you on her own, before being startled? You'd quickly discard all the information you thought you'd learned from the video.
At first I thought the brilliant move on Valve's part was deciding to teach players through a cinematic, but really every game's cutscene and trailer and box art have always been teaching players. Valve's brilliant move was noticing this, and making sure that what they taught their players was actually true in the game.