Tension is the number one element of plot. If you don’t believe me, just go read any good book or play any good game. It’s not to say that you should focus on tension more than anything else when designing a story, but when designing plot it needs to come first.
To start with a definition, tension is when the character has a goal, but things happen to make the goal seem impossible. It’s always better if the audience wants the character to succeed in the face of impossibility. This can range from the romantic interests getting in an argument to the antagonist getting ready to behead the protagonist.
The first principle of tension is that it (on average) must always be increasing until the turning point/climax (there is a difference between the two, but I’m not going to go into it). Breaks are allowed, but afterwards the stakes must be higher than they were before. Take Half-Life 2; you get a break at the new Black Mesa facility where they teach you how to use the gravity gun, but then you’re thrown straight into Ravenholm. A short break, then ramp up the tension.
Games have unprecedented potential for building tension, though they also have pitfalls that don’t exist in other genres. From my experience, I’ve noticed three main ways that games build tension: external forces, failure, stupidity (which in a sense is a kind of failure).
External forces usually build tension when the player is unaware that such a threat exists and as such cannot stop it. Quite often this is what sets the hero off on his quest, much like the Great Deku Tree telling you about his curse. Now, obviously we got drawbacks here. Enemy actions is one of the few things it’s ‘legal’ to pull out of nowhere, but if you do it too much it can start to feel a little cheap, as if your drawing the story out for the sake of drawing it out. The above mentioned Half-Life anecdote is another example of this because you have no idea you’re about to get attacked. Well, you’d have some idea if you paid attention to the foreshadowing, but Gordon Freeman doesn’t have any idea.
The second tool is potent in novels and movies, but in games it’s dangerous. To invoke it, you essentially have to force the player to fail, and quite often the player doesn’t want to fail, and they might feel that you’re forcing their actions. The first example to come of mind is the opening sequence of Super Metroid where you come looking for the baby Metroid and Ridley’s there waiting for you. After fighting for a bit, he flies off, and you’ve failed in your goal to stop him. I should say, though, that Samus failed, not the player since that fight is impossible (Ridley is programmed to run whenever he takes enough hits or your energy falls too low).
In the Metroid example, I think this device works because one of the main points of the game is to find the power-ups and get stronger. Then, the next time you show down with Ridley in the depths of Norfair, you’re ready. However, most games seem to avoid this technique because they don’t want to force the player to fail.
The final method is something else the game designer needs to be cautious of. The first example of tension by stupidity is also from OoT when Link opens to Gate of Time. I suppose this is more ignorance than stupidity, but I’m putting them in the same category.
First off, a warning: this device is dangerous because the player may realize ahead of time that doing something like this is stupid, and then you force them to do it anyway. This is why most games seem to avoid this technique too, and in a living story all about choice, forcing is a very definite no-no.
OoT pulled this off well because you as the player (assuming it’s your first time) have no way to know that this is a mistake, and Zelda seems to think it’s for the best. So, the best way to build tension by this method is to make the player think this is the right choice even when it’s dumb. You’ve got to be pretty convincing though.
Tension by failure and stupidity, however, have a special place in a living story because the story doesn’t have a set path. When given a choice, if the player does something stupid or fails, we can use that to build tension instead of just forcing them to restart. And even if we have wonder players who never make mistakes, we can just throw external twists at them.
Because of this, a living story has can create tension in new ways because it doesn’t need to force players down a specific path. Most games seem to avoid tension by failure or stupidity because they realize the costs, but as long as you don’t force the player into it, it can be a powerful tool.