Health Study

In most games, health is the primary or only feedback. After a skirmish you look at your health bar or number and check how good or bad you perfomed. Sometimes you don't come out of a skirmish at all, but that's just another aspect of the feedback system Health.

Generally one can see a game as a black box. You put in your controls(keyboard, joystick, gamepad commands), the game does a lot of things mostly unknown to us, and in the end it provides two types of outputs. It gives you a multitude of indicators, that do provide feedback such as a 3D view or a hit indicator. While theese are a must for playing a game, they generally don't convey the message "you are good" or "you are not good". When you see a red flash on the screen, it usually means, that you were hit by a weapon, but this happens probably a lot, so while you can react to the flash and try to get out of the danger zone, you cannot directly measure your performance with it. The second type of feedback is your health. You can directly measure your performance when looking at your health decrease. The ultimate feedback is to survive or not to survive a combat situation.

A good health system should provide strong and significant feedback and that with little delay. It doesn't do any good realizing that you handled things badly after hours. You'll most likely throw away the game and never touch it again. We want feedback now! If we perform poorly we want to know when we still have the chance to correct it. If the average health loss during a skirmish would be between 2% and 3% of your health, we'd have a hard time figuring out how we perform, so there should be a signifficant decrease if we screw up.

The most primitive approach to a health system violates both requirements. You start a game with a given number of HP and over the course they can only be diminished. You cannot regain Health.

This is a diagram of such a game. You start with 8000 HP. The game designers estimated that you cannot do better than the red area(leave it upwards). Well perhaps you can top that after years of training, but the game's supposed to be played without that. So at the end of the game which might take you perhaps 15 hours you'll surely have less than 3000 HP left. Since a game without challenge would be meaningless, the game designers defined the minimum skill you need to show to be the the border to the blue area. So as long as you stay within the red area, you don't need to improve to finish the game. When you however enter the blue area, you need to improve, because otherwise you're not going to have any HP left at the end. When you enter the green area, you'd need to perform at the maximum estimated performance or better throughout the remainder of the game to survive. If you had that skill, you wouldn't enter the green area, so you're as good as dead. You just don't know it. The violet line shows the path of a bad player. Since he doesn't know how long the game is, he won't realize that it's over bevore he's dead. No he would need to go back many hours to have the chance to correct things. A really bad System, don't you think.

To overcome this problem, the game could be split into several missions. You start each mission with given HP. You either survive, or you don't. I've created another diagram of such a mission that's perhaps 15min long. This mission will be used to compare the different approches later. The allowed health loss will be the same. The only difference will be how you regain health.

The game difficulty should ensure that the player is a bit above the blue curve, which is the least skill required to win, but not too much. If you stay wihtin the red area, you have a chance to survive. If you enter the green area, do a reload. Wait you don't know when you do that :). As earlier you're not expected to be able to do better than the read area. This mission is composed of three major skirmishes(at 5, around 13 and around 21) plus a few single enemies in between. Since the toltal loss when reloading is limited to 15min(the whole mission), this system is better, but the green area is still very large and a rookie player will not recognize when he comes near the green area and has little to no chance to survive the whole.

Health Items, reactivley placed

This is the next system i want to discuss. Now you can regain health by picking up medkits. You also only start the mission with 100 HP and you can't have more than that. Pretty straight forward. The medkits are placed reactively. That means, that any expected loss of Health is made up with medkits afterwards. It looks like this:

I've changed the digram type from area to line. So you can't do better than the red line and you shouldn't be able to do worse than the blue line. But wait you can do that:

Here the player(violet) performs slightly worse than the least allowed skill blue. It takes quite a long time before he realizes this. So this system is not that good either.

Checkpoints

The checkpoint system lets the level designers place checkpoints within a mission. At every checkpoint you are completely healed once.

The checkpoitns are placed at 8, 19 and 25. Notice the dips are a little deeper. This means that if you perform below the minimum skill, you'll die very fast. It's a good system, it forgets all mistakes if you just manage to survive until the next checkpoint. It gives you good response when you drop below the blue line. Yet the 2nd incident around 16 is not quite as challenging as it should be. You shouldn't be able to drop below the blue line and survive.

If you perform slightly worse than required, you'll die in the first and third skirmish. But you'll survive the second. That shouldn't be, but it's still a good system.

Health Items, proactively placed

In this system, the game gives you medkits worth exactly the amount of HP you need to survive the next section. In case you wonder, it gives you 190 HP just like the reactive system did.

Whenever you'd drop below the blue line, you're sure as hell dead soon. All except the first enemy at 2 are potentionally deadly if you perform close to the blue line. In this case i don't need to post the diagram where the player performs slightly worse than the allowed blue line, i think it's pretty obvious what'll happen. I'd say it's a good system.

Constant Regeneration

In this system you regain HP slowly over time even when you're attacked.

Look at this, if played fast it looks almost like the first system, where you cannot regain health. If you perform poorly you'll die much later. It appeals to novice players tough, because a little time can make it forget the most grievous mistakes.

But you can have that with checkpoints too, that don't take away the challenge, and don't force bordom upon you.

Idle Regeneration

In this system you regenerate health when you aren't attaked for a given time.

It's slightly more challenging, just like the checkpoint system, but even more boring than the last.

Fast Idle Regeneration

This system regenerates your health points very fast whenever you're not attacked for a given time.

It makes a joke of single enemies, because you could go get yourself a coffee while killing them without consequences. In the other regeneration systems, this was at least punished with the time waiting for your health to replenish. And the 2nd skirmish around 17 is not nearly challenging.

Applications for Regeneration

Now that i've essentially wrecked the idea of Health Regeneration, i'd like to present two game ideas, that might go well together with health regeneration.

Assume that a game consists of many very small yet potent challenges. You don't go into a full skirmish, because you wouldn't survive that. You pick your targets one or two at a time. Yet the game should be fast paced and there should be a lot of enemies. Think of the amount of medkits required to refill your health after every one or two enemies. It could force you into actively looking for them, wich goes against the idea of a fast paced game. The solution "Fast Idle Regeneration".

Since you only get 35 HP maximum, almost every encounter is a challeng by itself. You don't need to worry about your health over the whole game. You just need to survive the next encounter and everything will be fine, but it keeps you always on your toes.

A second application could be a game like Serious Sam. It throws wave after wave of enemies at you. Assume that the game designers don't want you looking for health, instead want you to fully concentrate on the combat itsself, it could work well with a regeneration system.  You have very little HP, but they regenerate roughly at the rate you're allowed to loose them. When you see you bar dropping you better tune yourself up, because it only forgives small errors and not many of them. Since your health bar fills and empties within seconds, it gives you the highest possible feedback. And it can go on almost forever.

It could work, don't you think!

In the end i must say, that i changed my opinion over the course of my study. I remember really liking regenerating health(like in the original Halo). That's because i don't like to be pushed too hard in games and it gives me the option of doing things my style. My study however showed that you can have a forgiving game also with other health systems, that provide better feedback and enforce the skill constraints a lot better. From this point of view i like the "Proactive Medkits" system the most. In reality the level designer would of course spread the health kits out a little to make the princliple behind the system less noticable.