Realistic damage models

This is part two of the Weapons series. Read Part One: Realistic weapon behaviors.

Warning: This article will be discussing damage to the characters and contain detailed  descriptions of wounds and their effects.

If you played any recent games that involve combat, you’d have noticed that they all use “hit points” to model damage. They may sometimes be called “health,” “vitality,” or “physical condition,” but the underlying logic is the same: You get a number representing how close a character is to death. As a character gets attacked, any damage they sustain gets subtracted from the available hit points, and once you reach zero, you die. Simple, and elegant, right?

Well, simple it may be, but this model is also completely unrealistic. It forces many weapons to be less useful than they should be; it takes away from the challenge of the game; and finally, it turns combat into a war of attrition where the player and enemy take turns shooting each other until everyone on one side is dead. All of these things are undesirable in a realistic game.

Life is full of complex balances and trade-offs, and a realistic game will seek to replicate that as closely as possible. So what is this going to look like when it comes to damage?

Realism

In most games, getting shot in the leg is a good thing. You take minimal damage and otherwise proceed unhindered. That would not work quite like that in real life.

No human has a hit point rating. When people get hurt in combat, they can’t just go on as if nothing happened until all their life points are gone. In a realistic setting, even if all you got was a flesh wound, you’d start to limp at a minimum, but if the bullet hit a bone, you may not be able to walk or even stand anymore.

To model this correctly in the game, our weapons won’t have any damage ratings. Instead they’ll be rated for the type of projectile they fire, and the energy with which the projectile leaves the barrel. From this we can calculate how much energy the projectile loses from air resistance on its way to the target.

If the target has armor, it will slow or stop the projectile. If the projectile is stopped, there may be no damage at all or some blunt damage depending on the armor type and energy involved. If the projectile did penetrate the armor, things will get bad for the target.

In the previous post we talked about accuracy and how hits are determined. So at this point we know: 

1. where the target has been hit,

2. with what kind of projectile,

3. and with how much energy (how fast) the projectile hit.

From all this data we can generate a realistic wound by looking at the body part that’s been hit. The system looks at what organs or structures there are, and calculates how much damage has been caused based on the velocity of the projectile and its shape. It’s possible that the bullet will pass through-and-through, as is common with small-caliber armor piercing rounds. In that case it may hit additional objects.

So now we have calculated one or more wounds, e.g. a broken leg, or a damaged eye, a direct hit to the heart, or an arm flesh wound. Just reading this list, you can probably imagine how each of these would limit a character. Some injuries may have more complex outcomes, when they don’t drop the target outright, but limit the character's ability over time.

Depending on the severity of the wound, there will be periodic heal/die checks. Some wounds will be life-threatening, in which case we’ll calculate a survival chance, and check frequency rate. Passing the heal check doesn’t mean the wound is healed, only that it’s no longer life threatening and the character will survive. Medical aid will change the odds for each wound, improving the chance of survival. Medical aid can also reduce the frequency of survival checks, so in some cases it buys the time to get the character to a proper hospital.

Now that may sound scary, but it should make for a more nuanced and interesting gameplay. You’ll have more options for selecting the right kind of weapons for all members of your party, depending on both their talents and the objective.

Take for example the small concealed pistol. There’s a reason they exist in real life, but in your typical game they are pretty much useless. With this system, they can be useful once more, provided you can avoid the armored parts of your target and hit a sensitive spot.

Same goes for armor and combat tactics. Do you bring heavy armor to the fight hoping to stop any rounds headed your way, or do you rather focus on not getting hit at all? Heavy armor will make you slower and more conspicuous, while light armor or none at all may increase your agility, but makes the consequences of getting shot much more serious.

As a result of balancing the objectives with risks, as the game goes on, every player will end up building a very unique party, best suited to their playing style.

That’s it for today. Our next post will deal with encumbrance and movement.

Realistic Weapon Behaviors

Here at Shy Snake, we have a focus on realism. Let us explain how that carries over to weapon design and balance.

The nuts and bolts

We start with the real properties of a weapon, the real basics such as how many rounds it holds. We don’t use “proxy” statistics such as bursts or taps. No weird logic that leaves you with a pistol holding 4 rounds while somehow being as accurate as a sniper rifle.

This means the weapons will have the same realistic controls you would expect in real life. Most will have a single-shot mode. Quite a few have a burst mode, or full-auto mode. You may remember our earlier post, in which we talked about timelines. In a timeline-based model, if a weapon has full-auto mode, it’s 100% up to you how long you want to hold that trigger: fire a short burst or rock’n’roll until you’re empty -- completely up to you.

Accuracy and chance to hit

Here we make a pretty dramatic break with most squad-based strategy games. Rather than using a basic “hit chance” with modifiers for range and possibly cover, we go in a different direction. Our system is based on CEP (Circular error probable).

While it may seem like a lot of fairly abstract math, in practice this concept is very simple to explain.

It goes like this: The player specifies an aim point for a character. The system then calculates based on skill, time spent aiming, situation, and weapon, where the shot actually goes. From there it determines hit or miss.

This also means things such as hit location fall out of the calculation naturally. A skilled shooter with a good rifle and time to aim should consistently miss by just a couple inches at most at normal ranges. That’s probably going to be both a hit AND hit something important. A less-skilled shooter panic firing a pistol is much less likely to hit what they aimed at, and may well be a hazard to those around them.

There are three primary factors that will determine where the shot actually goes.

1. How well did the shooter do at pointing the weapon in the right direction? Based on their skill, the time they spent aiming, and conditions such as standing, kneeling, or prone.

2. How accurate is the weapon? Does it put the round right where it’s aimed or does it vary widely on it’s own?

3. How stable is the round once fired? Does it veer wildly off the intended trajectory?

At typical combat ranges the first is the dominant factor. It’s also where a lot of the gameplay balance for the various weapons happens. The powerful heavy weapons tend to be slow to aim and vice versa.

There's a reason the military carries assault rifles

So just as in the real world, you wouldn’t want to use a sniper rifle to breach a room, just as little as you’d want to use a pistol for picking off an unaware target at long range. These curves are actually generated from the length, weight, and grip of the weapon, and are unique for each.

The player will have a wide range of options for servicing the enemy.

Recoil and burst or full auto fire

Once the player has aimed and begins to fire, the accuracy model continues to be important.

One thing almost all games get wrong, is that burst fire doesn’t affect the chance of the first and consecutive rounds fired hitting their target. In our system, once the first round is headed downrange, the recoil of the weapon is calculated against the shooters stance and ability. This degrades the aim of the weapon.

As a result the next shot will be less accurate; and each subsequent shot will be even less so, until you reach the point where the character’s ability to control the weapon will stabilize any further loss of accuracy. This means that low-recoil weapons are more desirable if you plan to throw lots of rounds downrange in a hurry.

For a look at how our game deals with damage and damage modeling, stay tuned. That’s a subject for another post.

What is it all about?

In the future, all LEDs are blue.

Psst! Want to know a secret? I’ve been working on the script for the new game, and got a rough outline done!

Want to know what the game is going to be about?

It’s going to be set in a not too distant future, so you should still recognize the tech. The difference will be, that it will just work. And there will also be lasers and railguns and other futuristic weaponry. And genetically enhanced soldiers.

Right, that’s what the game will really be about: Leading a squad of genetically enhanced warriors in a fight to save the world. Because anything less doesn’t require an international squad of super-soldiers.

So as a player, you’ll have your main character, who is the squad leader, and a selection of similarly enhanced troops to support you. Each of them has a specialty, like sniping or explosives, or maybe even interrogation. Don’t hold me to any of that though, because the game is still pretty much a work in progress, and everything can change. But you get the idea.

Between deployments you and your buddies chill in cryogenic storage pods. Why? Well, on one hand, it’s the future, and apparently it’s the thing to do. Also, if your government-funded project just sank millions into creating a handful of super-soldiers, you don’t want them to just be hanging around aging, so that in ten years you need to make and train a bunch of new ones. That’s just wasteful, and even in the future, the money is tight.

So about that government project. It has a lab and a whole secret base where the scientists can do their research and keep an eye on the cryo-pods, to monitor the cryogenically stored soldiers and revive them as needed. Like, when the world is in danger.

When the game starts, you find your character waking up in their pod, and the lab has obviously been attacked while you were sleeping. The whole place has been turned upside-down and a bunch of people have been shot. Nasty business.

Now, it’s going to be your job to figure out who done it, what they were after, and how to stop them.

Sounds good so far? Wait till you see the rest of the story.

But if you were wondering what I’ve been up to since the last blog update, now you know.

By Alex Maier, Shy Snake founder

Creating the world

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Everything in a game has to be created from scratch, either by you or by someone else: walls, floors, furniture, and of course the characters themselves. This is called game level design.

When you create objects for the level, you have to teach them everything about themselves so that they appear in the correct spot in the world and also look right. It goes kind of like this.

Object: What am I?
Me: You're a carpet floor tile.

Floor tile: Am I shiny? Am I smooth? Am I made of metal?
Me: No, you're not very shiny at all, you're kind of bumpy, and you're definitely not made of metal.

Floor tile: What color am I?
Me: You're this kind of unexciting institutional green, because you're in an office building.

And so on, for every little thing that exists in the world. In order to make the task of game level design a little bit less daunting, I use Unreal Engine 4, shown in the screenshot.

I spent the last couple of weeks creating and fine-tuning materials for the walls and floors of the building used in the first level of the game and then placing props, such as office furniture, in the different rooms. Yes, I made a bunch of different carpet tiles. How did you guess?

It’s quite exciting to see a world come together, let me tell you. I can’t wait to show you the first demo!

And now, back to work.

By Alex Maier, Shy Snake founder

Shy Snake has a logo

So, big news this week is that our company now has a logo!

Quite a bit of time and thought went into designing it, and we're happy with the outcome.

At first, we wanted to focus on the shy nature of the snake, and there were a number of drafts that had snakes hiding behind flowers, leaves, or even their own tails. True story, some real snakes use their own bodies to "hide" when they're shy, too!

After a while, we settled on a logo showing a snake with a joystick, to symbolize gaming. If snakes played games, they'd probably have an easier time using a joystick, compared to a keyboard or a game controller. So joystick it is.

We hope you like our new logo as much as we do.

Hello world

Shy Snake now has a home on the web, where we can tell the world what we're up to.

Right now, we're working on our first game.

It will be a turn-based 3rd-person game, set a few years in the future. We don't have a name for the game yet, but we still want to tell you about it.

The two main things we think many gamers will like about our game is the timeline-based approach to the turns, and a realistic damage system.

Timeline-based turns means that the turns for each character may have different duration, depending on the character's attributes for that particular action (physical or mental quickness, for example), or any impairment (such as injuries or fatigue.) 

What does this mean for gameplay? It means that if your character's turn is 0.5 seconds long, you'll get to go again after 0.5 seconds of game time have elapsed. Other characters' turns may be longer or shorter, and the game will pause when it's one of your character's turn to go.

This also means that you won't be trowing away action points at the end of the round because what you wanted to do didn't fit cleanly into how the game was dividing the time. We'll calculate how long a particular action will take a character, and they'll be done with it when they're done. And that's when they get to do something else.

The realistic damage system means that we won't just calculate whether you hit your target (or the enemy NPC hit your character), but we'll also calculate hit location, and base the impairment of the injured character on that.

In simpler words, this means that if the character gets shot in the head, no matter how many damage points they have, they will probably have to lie down for a while. A really long while.

So, this is it for today. There'll be more updates later, so stay tuned.