The New Chance-to-Hit system, also known by its short name "NCTH", is a feature now in the works for the first release of HAM 4. It is destined to become the most significant feature in HAM ever. It consists of a complete rework of the entire shooting mechanism for JA2 1.13, rethinking the way weapons are aimed and fired.

This feature is not yet available to the general public (it is not even completed yet). It will be made available with HAM 4.0 alpha.


The foundation of this system lies in replacing the entire "Chance-to-Hit" system used by JA2 1.13. Flaws in the original system meant that gunfire was too expectable, too reliant, and as a result, too accurate for balanced gameplay. In an effort to crush exploits and provide a more realistic system, Headrock began by rethinking the way CTH is calculated, primarily splitting the application of aiming and shooter-related circumstances from the application of gun-mechanics. In other words, making sure that the player can't make a gun 100% accurate just by aiming enough, instead having to suffer some inaccuracy resulting from the gun's properties (such as its Accuracy value). As the system evolved, it became clear that it could be used to improve many of the different aspects of aiming and gunfire.

General DescriptionEdit

NCTH is an extensive attempt at making a realistic shooting system that behaves more like real life. Built mostly from scratch and replacing the existing Chance-to-Hit system, NCTH simulates the various actions, considerations and effects that take place from the moment the shooter raises his gun to fire to the moment the bullet leaves the barrel. While it doesn't get down to the gritty details of gunpowder and muzzle velocity and all that stuff, it does simulate closely how a shooter would take aim at his target, compensate for various problems, and suffer unavoidable factors related directly to the gun he is using.

The system is built in several distinct steps, which again cover everything from aiming the gun to firing the bullet. It is organized in such a way that each element is nearly entirely independent from the others. This has several benefits, as will be explained below. In the meanwhile, here's a generalized list of how things proceed during the firing action:

  1. The shooter brings the weapon up to fire. This is called "Snapshot" or "Base" mode.
  2. The shooter spends time to aim his gun as well as he can on the target. This is called "Aimed" mode.
  3. The shooter compensates his aim for target movement or firing beyond the gun's maximum range.
  4. The trigger is pulled, and the game records the position and direction of the muzzle.
  5. The bullet leaves the barrel and establishes a trajectory through the air.
  6. In Burst/Autofire mode, the gun recoils in a specific direction. The shooter may get a chance to fight the recoil and try to put the muzzle back on the target before the next bullet comes out.

This sort of segmented structure has several benefits which will all be explained. In general however, it gives modders an easier time by giving them plenty of ways to mess with individual parts of the system without messing with others, and it also makes life simpler for future coders to adjust any segment they see fit.

The Simple ExplanationEdit

Unfortunately, explaining how NCTH works would take an entire article (see below, hehehe). Then again, explaining how the old CTH system worked would've also been difficult. Fortunately, what the player actually needs to know is very little, and on-screen indicators will hopefully make it simpler to use than it actually sounds.

Let's start at the beginning. Instead of the old CTH indicator (that bar hovering above the target), NCTH has a new indicator that is designed to make this system as intuitive as possible during gameplay.

The NCTH indicator has two parts:

  1. A large outer circle, known as the Maximum Aperture. For basic understanding of NCTH, you can ignore this circle completely.
  2. A set of crosshairs extending outwards from the center. This is the more important part!

The basic use of this indicator is extremely simple: Just make sure that, when firing, the distance between the crosshairs is as small as possible. The smaller the distance, the more likely it is for your shot to hit the intended target!

In fact, if you make the distance between the crosshairs equal to or less than the width/height of your target, that would be a guaranteed hit (at least, in most cases).

Decreasing the distance between the crosshairs is usually as simple as adding "extra aiming clicks" to your shot, using the right-mouse button, just the same as it worked in the older system.

Of course, once you get the hang of this, you'll quickly notice that at a longer distance, it can be virtually impossible to get those crosshairs close enough. That's when you need to understand how the crosshairs and the circle around them interact, what they actually mean, and how to improve your chances.

Aperture, Muzzle Sway, and everything in betweenEdit

The new CTH system works internally quite differently from the old one. While the indicator is a good way to tell how likely you are to hit your target, understanding how to alter your chance-to-hit is obviously crucial. For this reason, you need to understand the more complex things that go on when the NCTH system kicks in.

We'll start with the indicator again, and this time try to understand how it works. Let's reiterate the two distinct parts of the NCTH indicator:

  1. A large outer circle, known as the Maximum Aperture.
  2. A set of crosshairs extending outwards from the center.

We already kind of understand the crosshairs. The indicate how far from the target's center your shots might go once you pull the trigger. So obviously, the smaller the distance between them, the more likely you are to hit the target. Make the distance small enough, and you can guarantee a hit. However, as stated above, actually making the crosshairs smaller than the target, or in fact anywhere as small as the target, can become very difficult - especially at longer range.

For this reason we need to understand what the larger circle stands for, and also the nature of its relationship with the crosshairs.

Maximum ApertureEdit

The larger circle in the indicator is known by the enigmatic name "Maximum Aperture".

Your "Maximum Aperture" is basically described as the maximum distance your shot might stray from the center of the target if your gun is completely unaimed. To achieve such bad aim, you'll basically need a drunken injured soldier, with a massive gun, firing from the hip at a target they can't see.

Most characters, however, will hold their guns steadier, and extra aiming clicks serve to make it even more stable. As the gun gets better aimed, the actual aperture (that is, the distance the bullets may actually end up from the center of the target) becomes smaller. This is what's indicated by the set of crosshairs: They show the final result - how much the aperture has become smaller thanks to the shooter's skills, gun handling, and any other factor involved.

What's important to understand is that the two are invariably linked together. The larger your Maximum Aperture circle is, the harder the shot is going to be. Apply the same amount of extra aiming when the outer circle is much larger, and your final results will not be nearly as good as when the outer circle is much smaller.

Reducing the size of the Maximum ApertureEdit

Naturally, if your shot accuracy depends on the size of the maximum aperture, then your goal is to make that aperture as small as possible! Of course, herein lies the problem: The size of this outer circle is based mainly on two factors that you (the player) cannot do anything about:

  1. Range to target.
  2. The inherent accuracy of the gun.

In other words, the further you are from your target, the larger the Maximum Aperture circle will be. And, a gun with lower accuracy will also have a larger Maximum Aperture circle than a more accurate one, even if the range is exactly the same.

Therefore, when you move closer to the target, the maximum aperture will become smaller, making the shot easier.

Of course, these things are only PART of the equation. In fact, the Maximum Aperture only indicates how difficult a shot would be if your shooter is truly inept. When any other factors besides the range and the gun are taken into account, we can start seeing our shot becoming much, much easier.

Actual Aperture / Muzzle SwayEdit

The Outer Circle only indicates how LOUSY our shot can be. What we're really interested in, however, is how accurate we CAN be, or even how accurate we actually are for any given shot. This is represented by the crosshairs on the NCTH indicator. It is also called the "Muzzle Sway" or "Actual Aperture", depending on Headrock's mood at the time.

So, Actual Aperture shows how far your shot might sway from the target's center after taking into account everything that doesn't have to do with range and gun accuracy. This is, not surprisingly, a whole ton of factors:

  1. How good our shooter is.
  2. The number of extra aiming levels we've paid for.
  3. Scopes and laser pointers which can improve aim.
  4. How large our gun is, and whether or not it has been stabilized properly.

By increasing the above, we can make the shot more accurate. This is indicated by the Muzzle Sway Crosshairs. The better our conditions, the closer together these crosshairs will be. In fact, in the right conditions it is possible to shrink the distance between the crosshairs to virtually nothing, even at massive range where the Maximum Aperture circle is absolutely huge.

The relationship between the Outer Circle and the Crosshairs is therefore obvious: The more difficult the shot, the larger the circle. The more effort we put into aiming (and the better equipment we install on the gun), the easier the shot. If we put enough effort into it, we can make even a difficult shot highly-accurate.

Conversely, by the same logic, the closer we are to the target, the easier the shot, and hence we need less effort to get our bullets on target.

Of course, it's never as simple as that, so let's go on to explain some more about what reduces or increases Muzzle Sway.

Base Muzzle Sway / SnapshotEdit

When first using the NCTH system, you might notice that the Crosshairs (Actual Aperture) usually don't start as large as the Outer Circle (Maximum Aperture). They usually extend a little into that circle, even when you don't apply any extra aiming clicks.

Why is our shooter not as "inaccurate" as he should be?

Before we apply extra aiming, our shooter already gets a chance to be a little more accurate than "absolutely totally insanely innaccurate", which is basically what the outer circle would indicate. Our shooter may have spent no time on aiming the gun correctly, but they are still pointing the gun in the general direction of the target.

This is called "Snapshot" mode - raising the gun towards the target, but not yet taking any time to aim it more than the absolute minimum. You can call it "shooting from the hip" if you want, though it does apply to any weapon, including pistols, which aren't ever fired from the hip anyway.

Why would you want to shoot this way? In simple terms - faster is better. Snapshots can be great in close-combat, which is what they're designed for. In extreme close quarters, aiming is largely irrelevant - the target is too close to miss. In this case, even basic aiming is usually enough to put most if not all shots on target. Remember of course that until this is changed, Burst and Autofire never take advantage of extra aiming, and are therefore always used in "Snapshot" mode.

Base Muzzle Sway is given to the shooter for ANY shot they make, a sort of constant bonus. How much you actually get depends on a LOT of factors. The most important ones in normal combat are the shooter's Experience Level, as well as the size of the gun. The smaller guns are easy to bring up into the correct direction even without aiming, while larger weapons prove more troublesome. Other factors, such as injury, fatigue, morale and so forth are also taken into consideration, and may increase Muzzle Sway proportionally. Stance can also be important, as it's harder to get a gun properly pointed quickly at the target when lying flat on your belly.

Of course, for anything except really close combat, Base Muzzle Sway is nothing more than a slightly-better starting point for improving your shot further through aiming. Still, with the largest Base Muzzle Sway possible being around 33%, this can be invaluable - it means the distance between the crosshairs shrinks to 66% of the size of the Maximum Aperture circle, which is no laughing matter. Of course, the average Base Muzzle Sway tops out at around 20% - for better results you need to gain Experience!

To get actually-accurate shots, of course, we're going to need to aim a little. But first let's ask a different question: How accurate can we get?

Minimum Muzzle Sway / CTH CapEdit

One of the major differences between the old CTH system and the new one is based around the idea that most characters can't possibly stabilize their gun enough to keep it trained smack on the center of the target. Olympic shooters train for years to keep their sights on the target long enough to keep them there when the trigger is pulled. Most shooters will have at least some jittery movements, and this is represented by a value commonly known as the CTH Cap.

In essence, this CTH Cap determines how low our Muzzle Sway can get - EVER. Determined by our shooter's skills, this can vary anywhere from 0% Muzzle Sway (perfect aiming!) all the way to 100% Muzzle Sway (a virtually hopeless shot unless the target is standing right in front of you). Of course, most characters are neither perfect shooters nor hopeless shots, and the average CTH cap lies at around 25% - meaning that a shooter can never have less than 25% of the maximum allowed Muzzle Sway for any shot, regardless of how much time and effort they spend on aiming their gun.

This cap is an important factor to remember when we try to aim our gun. In fact, the amount of muzzle sway reduced by extra aiming levels depends directly on this factor.

Aimed Muzzle SwayEdit

To make the crosshairs small enough to ensure a hit on the target, or at least increase the probability of hitting the target at all, we're going to need to decrease muzzle sway further. This is done the same way as it was done in the old system - by adding Extra Aiming Levels, at a cost of APs.

Each extra aiming level decreases muzzle sway by a certain amount. The actual amount depends on a lot of factors, similar to the calculation of Base CTH. Marksmanship is the primary factor for this calculation, with more accurate shooters being able to reduce muzzle-sway more with each level. Let's list at least some of the things that influence this:

  1. Skills (with Marksmanship being the primary influence here)
  2. The size of the gun (longer guns are EASIER to hold steady)
  3. Stance (It's easier to keep a gun steady when lying down)
  4. Injury, Morale, and other situational factors
  5. The number of aiming levels allowed by the gun (Read more about this later)

Assuming that all these factors are at their optimal levels (which is rarely true), the shooter will be able to reach their CTH Cap (Minimum Muzzle Sway) once the last aiming level has been added. At closer ranges, it may not be necessary at all to aim that well to score a guaranteed hit, but this changes at around 10 tiles of range or so. Beyond that point, aiming properly can become absolutely crucial.

Finally, it's important to note that in NCTH, each aiming click will remove LESS Muzzle Sway than the previous click. On guns with 8 aiming levels allowed, that means the last level can potentially reduce Muzzle Sway by negligible, if not nonexistent amounts. However, it's important to remember that at very long distances (where such guns are used), every single point of muzzle sway removed may mean the difference between a guaranteed hit and a 50% chance to miss the target. This is obviously crucial!

Recoil, Target Tracking, and Drop CompensationEdit

To complete the package, NCTH goes so far as to realistically simulate things that are outside the normal business of aiming and shooting. These extra considerations are calculated separately, and will cause the muzzle of the gun to move based on complex formula.

Of course, this article isn't about formulae, it's about explaining how to use NCTH. So we'll do our best to explain how these new systems work from the viewpoint of the shooter.

Drop CompensationEdit

JA2 doesn't actually calculate gravity or physical forces. It's a 2D game, after all, and for all its complexity it would be hard to bridge that gap. However, it does do all sorts of things to kind-of sort-of simulate the various forces that act on a bullet while it's in the air.

The most important force is Bullet Drop. All bullets, once fired, are constantly dropping towards the ground - in fact, they fall towards the ground as fast as they would if they were simply dropped from your hand. The only reason they cover so much distance while doing so is that they are travelling at terrific speeds. The drop only becomes "noticeable" once the bullet slows down, thanks to air resistance.

In JA2, bullet speed doesn't exist - all bullets move equally fast. In addition, they don't constantly drop towards the ground like in real life. They only begin to drop once they pass the "Maximum Range" of the gun that fired them - a value shown clearly on the description box for the gun. After reaching that maximum range, the bullet will hit the ground within a few tiles. Therefore, the gun's "Maximum Range" is sort of a substitute for actual bullet velocity - it determines the rough distance the bullet can possibly travel.

In NCTH, the same system is used. However, it also gives shooters something they can do about this, much like in real life: They can raise the gun by a few degrees towards the sky, causing the bullet to take something similar to a ballistic trajectory, hence increasing the distance the bullet can fly, and thus effectively increasing the range of the gun.

This automatically occurs whenever shooting at a target that's outside the gun's range. The shooter will attempt to raise the gun by the precise amount required to hit the target despite the bullet drop. If done correctly, this can increase the range of the gun by up to 15%!

However, this is somewhat of a difficult feat to accomplish. The gun needs to be raised by an exact angle. Raise too little, and the bullet will still hit the ground in front of the target. Raise too much, and the bullet will over-shoot the target.

To get it right, shooters need to apply their skill (primarily wisdom and experience level). The better their skills, the more likely they are to raise the gun by the proper amount, or at least close to the proper amount.

Naturally, shooters with little experience or wisdom will fail to do this properly. It's primarily a "last-ditch" measure, but can be very useful for suppression fire, where an actual hit isn't that important, just getting the bullets as close to the target as possible. Expert shooters, however, may be able to effectively increase the range of any gun they are holding this way.

Target TrackingEdit

Moving targets are harder to hit. This is a given, and no shooting practice is complete without a moving target.

The trick when shooting a moving target is two-fold:

  1. Keeping your sights on the target, which means matching the speed of your hands to the speed of the target.
  2. "Leading" the target - firing at where the target is GOING to be when the bullet reaches it, instead of where it is right now.

NCTH simulates this difficulty by putting the muzzle of the gun behind the target by default. It's only the shooter's skill, as well as the time spent aiming, that can help reduce this muzzle offset and put the bullets into the target rather than whatever object might be directly behind it.

To make for extra realism, NCTH also calculates the direction of movement as well as the distance - and the two are extremely important.

For one, a target moving exactly towards or away from the shooter will give no target tracking penalty whatsoever. The shooter doesn't need to lead the target, and keeping the sights on the target isn't more difficult.

Conversely, when the target is moving perpendicular to the shooter's line of sight (that is, directly left or right), it dishes out the largest movement penalty.

In addition, we use the distance the target has moved as an indicator of speed. Distance is measured as the difference between the current position of the target and the position it had when its latest round started.

Distance works in a unique way: Up to a certain number of "moved" tiles, the Target Tracking penalty grows and grows, simulating the shooter becoming confused by the target and having increasing problems putting the sights directly on top of it. Remember - distance = speed - a target that moved one tile since its last turn is slower (or at least less confusing) than a target that moved 5 tiles.

Beyond a certain number of tiles however, the Target Tracking penalty begins to shrink. This simulates the shooter getting "used" to the target's movement, calculating its speed, and adjusting his sights accordingly. The more tiles the target moves, the smaller the penalty gets.

The shooter's skills and wisdom are key factors here. They basically determine how many tiles the target must move to give its "maximum" penalty, beyond which the penalty begins to shrink. So a shooter with high skills might only be confused if the target moves 3-4 tiles, and be able to properly compensate for targets moving a greater distance like 10 or 15 tiles. Conversely, an unskilled shooter may be confused by any target moving up to 10 tiles, and only be able to compensate for targets that move more than that. Shooters with sufficient skill, aiming at a target that is moving a considerable distance, may actually be able to undo the Target Tracking penalty completely, essentially "leading" the target correctly in their sights.

Note that the range to the target is extremely important here too - it is FAR more difficult to aim properly at a target moving far from the shooter than one moving up close.

Recoil and Counter-ForceEdit

JA2's Burst fire mode and JA2 1.13's Auto-fire mode have both been using a simplified way of treating recoil between bullets. Each of these modes simply decreased CTH by a certain amount after each bullet was fired. While simple to understand, this produced unrealistic results - bullets that failed their CTH check simply sprayed in any direction, likely missing the target completely. It also meant that once CTH reached 0 thanks to these constant decreases, the rest of the volley would be a complete waste of bullets.

In real life, of course, things work very differently. Recoil causes the muzzle of the gun to move a certain distance in a certain direction (determined mostly by the direction and power of the gasses ejected from the gun while firing). In addition, shooting a long volley does not mean that the muzzle will always end up pointing at the sky, because the shooter can apply force to try and bring the muzzle back towards its target.

This is what the NCTH recoil system simulates - the interaction between the recoil force pulling the gun in a specific direction, and a shooter-applied counter-force that tries to push the muzzle in the other direction. If counter-force is applied correctly, the muzzle will move against recoil rather than with it. Over time, this can allow a shooter to bring the muzzle back towards the center of the target, scoring more hits even with later bullets in the volley.

Gun Recoil

In NCTH, each gun has a set of properties that define the distance and direction which the muzzle moves between every bullet. Normally, most guns pull upwards and slightly to the right. This recoil is applied for each bullet in the volley, and if left to its own will cause the muzzle to travel away from the target center indefinitely.


To prevent the muzzle from drifting away from the target's center, shooters will automatically attempt to apply counter-force. With this counter-force, they attempt to eliminate the movement caused by recoil, as well as correct any previous aiming errors, bringing the gun back towards the target regardless of how far away it was pointed when the volley began. Of course, if counter-force is applied incorrectly, it can either fail to negate all of the gun's recoil (causing it to keep moving away from the target, just slower) or to over-compensate and end up with the muzzle pointing away from the target in another, unexpected direction.

So, the shooter needs to apply just enough counter-force to undo recoil and previous aiming errors, but not so much as to have the muzzle pointing badly in another direction. Counter-force accuracy is a result of high experience, dexterity and wisdom, and it is virtually impossible to avoid errors completely unless shooting a gun with very minimal or no recoil.

In addition, the shooter's strength determines how much counter-force they can apply. If the gun has a very powerful recoil that outdoes the amount of counter-force our shooter can apply, it means that the gun will continue to climb, just less than it normally would. This means that at some point, the volley becomes "wild" and will no longer fly at the target. For this reason it's important to make sure that weaker characters don't fire the more powerful guns, or at least fire them in short bursts or autofire volleys.

Finally, counter-force can only be adjusted once every X bullets. This is harder to explain, so let's skip to an example of how this looks in game:

  1. The volley begins with a number of bullets (X) that apply their recoil FREELY, pulling the gun the same amount of distance and direction with every bullet.
  2. Once bullet X is fired, the shooter gets to calculate how much counter-force they need and try to apply that amount to the gun.
  3. For X number of bullets, the recoil and counter-force act against one another, changing the direction of the muzzle appropriately for each bullet.
  4. If the applied counter-force was exact, the muzzle should either have moved as close as possible to the center of the target, or is now pointing exactly at the center (causing a hit!)
  5. If the applied counter-force was too much or too little, over the past X bullets the muzzle has moved in a non-optimal direction, and may now be pointed in some direction other than the center of the target, based on the proportions between recoil and counter-force.
  6. After X*2 bullets, the shooter again alters the amount of counter-force he applies, again trying to put in just as much force as required to bring the volley back towards the center of the target
  7. Repeat until the volley is over.

The value of X in this example is called Counter-Force Frequency, and varies between mercs. Dexterity and Experience Level are again very important for increasing the frequency. Tracer fire is also very helpful here - when a tracer is fired, it immediately gives the shooter a chance to adjust counter-force, whether or not their X has been reached.

The end result is nothing short of spectacular, assuming a good enough shooter. Even if the first bullet in the volley began far from the target, correct application of counter-force can gradually bring the muzzle closer to the center of the target, possibly scoring a few hits despite the original aiming error! Of course, the downside is that many bullets would be expended this way, but it still allows the less-skilled shooters (or ones with less accurate guns) to have a chance to score hits at a distance.

Note however, that recoil and counter-force increase proportionally with range. At 2x the "normal" distance, recoil is twice as bad, and counter-force is half as accurate. As range increases, it gets considerably harder to place shots on the target this way without very high skills. However, if HAM Suppression is activated, then naturally even the missed bullets will give some benefit (suppressing the target).

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