Realism vs Arcade.

Real life is frequently binary. In a war, you're shot, you go from fully combat ready to down, disabled, or dead. Drive through traffic at 90mph and clip a car could wreck your car or kill you. Falling from a 3 story height will kill you more times than you will survive.

This isn't always fun, and it doesn't always lead to the best gameplay. For example, the effectiveness of modern rifles means that modern warfare is much more about communication, spotting the enemy and positioning than aiming and running through incoming fire. Games generally work best with a danger and punishment system - when you do badly, the player is in a position of danger, realises this and can correct it. This is as opposed to a more binary system where there is little or no chance to realise that you are in danger before you are given the heavy punishment.

So in fun games, we see health bars and recharging shields for our infantry, cars and tomb raiders.

Part of this is that real life gets to the punishment by skipping the danger - you could be a soldier off to Afghanistan, on patrol for 4 boring months before you even see a shot fired. The first bullet that goes off in your vicinity could go straight through you. You could die without even realising you were in combat, without even hearing the shot fired.

And seperately, part is because of what the player expects. For instance, in a shooting game, most players won't consider (even if they are forced to witness it first hand over and over) that they are in danger when bullets are flying past them, and thus won't correct for it. Players expect to be able to go at top speed in their Lamborghini, and will be frustrated if they keep crashing and losing their car and the race because of it, even though in real life going at top speed would be terrifyingly dangerous.

This is because players want to feel threat, but the threat they experience is perceived threat, not actual threat. A player as a lone knight charging down an army of men perceives that he is threatened, even if his health bar is ridiculously long. But he expects to be able to kill a peasant with a pitch fork, even if in real life such a peasant would be dangerous. When player's expectations are not met, more often than not they blame the game, not themselves.

So, we want a satisfying game. We want it to be immersive... (I believe that realism will generally lead to immersion. I'm not saying every game should aim for it. But for games where realism is within reach, go for it.) so let's say we go for realism. This means we can't just take the easy way out, up the perceived threat by exaggerating everything (enemy numbers and our own health) out of ordinary life. We need to match actual threat to perceived threat.

Now, actual threat is what we the designers adjust. We can establish that X mechanic is dangerous and will lead to death, but if it is actually dangerous enough that the player perceives it as dangerous, it is usually as it has been taught the hard way. The player has been shot one too many times by a hidden sniper, so now has to check every area before proceeding and isn't having fun, etc. This is where we bring out the ace in our sleve. Make X dangerous, and establish that it is dangerous. And then cheat, by making the player more powerful than he realises. This way, it's not that the player beat the situation because the situation is easy. It's because the player played really well! (or so he thinks!)

Now, I suppose that some younger players will still think that, in the lone knight scenario, they won because they were awesome. But having a huge health bar is just too obvious and isn't going to fool teen and adult audiences.

We can supplement the player's abilities to allow the player to skirt close to but around actual threat. Take Halo for example. In halo, the game subtly adjusts the sensitivity of the controls so that as you move your crosshair towards an enemy, your crosshair moves slightly faster, and as you move away from an enemy (such as going too far as you swing to aim at someone) your crosshair moves slower. In game, it's virtually undetectable, 99% of players will never notice. But it means that pretty much any time you want to do an action, you can actually do it. If you see an enemy squad below, picture jumping down, landing a grenade on a leader and then hosing down the little aliens in his squad, then you can do so first time 9 times out of 10. Rarely will you

So for example, imagine we have a realistic driving game. Perhaps it's part of a Borne Identity game you're making. You've already established with the player that colliding with oncoming traffic will total you, it's a real threat, but the player is likely to do it anyway. So what we could do, is implement the steering system like halo's to guide the player away from incoming cars. And when we go into a power slide, the computer can analyse if we're going to end up right in the path of an oncoming bus, and subtly adjust the friction on the road so that they are more likely to skid by it or pull up short.

Because it's what the player wanted to happen, they're unlikely to question it. They were just 'really awesome'.

The player's caution is fixed relative to the perceived threat. What happens when the caution is less than the actual threat? We can reduce actual threat by cheating.