New Chance to Hit (NCTH)¶

NCTH is 1.13's optional replacement for the shooting mechanics of the original game. It was designed by Headrock for the HAM mod series as "a complete rework of the entire shooting mechanism for JA2 1.13, rethinking the way weapons are aimed and fired", and was later merged into 1.13 itself. It is off by default — you enable it with the NCTH setting in Ja2_Options.INI (see Turning NCTH on or off).

The original system is referred to as OCTH (Old Chance to Hit). Which one you play with is a matter of taste: OCTH is more predictable and easier to read, NCTH is more realistic and more demanding. This page explains how NCTH works from the player's seat and how to actually hit things with it.

The deep-math reference

This page deliberately skips the formulas. The authoritative in-depth description is Headrock's own article on the HAM wiki — everything from muzzle sway to counter-force frequency is explained there in full detail.

A different philosophy¶

OCTH works like a classic RPG attack roll. The game computes a single percentage, shows it to you as a bar over the target, and rolls the dice. Aim enough clicks with a good merc and many shots become near-certain. Its flaws were the reason NCTH exists: in Headrock's words, "gunfire was too expectable, too reliant, and as a result, too accurate for balanced gameplay."

NCTH does not roll to hit at all. Instead, it models where the barrel points at the moment the trigger is pulled:

The shooter brings the weapon up ("snapshot" or base mode).
The shooter spends time (aim clicks) to steady the weapon on the target ("aimed" mode).
The shooter compensates for target movement and, if needed, for firing beyond the gun's maximum range.
The trigger is pulled and the game records the position and direction of the muzzle.
The bullet leaves the barrel and flies along that trajectory — hitting whatever is in its way.
On burst and autofire, recoil moves the muzzle between bullets, and the shooter applies counter-force to drag it back onto the target.

Every factor — skill, stance, gun, attachments, wounds — makes the cone of possible muzzle directions (the aperture) larger or smaller. The bullet is then fired at a random point inside that cone. There is no separate "miss handling": a shot that misses your target simply lands somewhere near it, and can perfectly well hit the crate your enemy is hiding behind, a different enemy standing next to him, or a teammate downrange.

Reading the crosshair¶

Under NCTH the old CTH bar above the target is replaced by a new targeting cursor with two parts:

A large outer circle — the "Maximum Aperture". This shows how far your shot could stray if the weapon were completely unaimed. Its size depends on only two things you cannot influence during the shot: range to the target and the inherent accuracy of the gun.
A set of crosshairs extending from the center — the "Actual Aperture" or "Muzzle Sway". This is the part that matters. It shows how far your bullets can actually stray after your merc's skill, aiming, attachments, stance and condition are taken into account.

The basic rule is simple: make the gap between the crosshairs as small as possible before firing. If the crosshair spread is equal to or smaller than the target, the shot is (in most cases) a guaranteed hit. Add aim clicks with the right mouse button, just as in the old system, and watch the crosshairs tighten.

At long range you will notice the outer circle grows huge and the crosshairs refuse to close all the way. That is NCTH telling you the shot is beyond your merc's current ability — move closer, aim more, go prone, or bring better optics.

Two Ja2_Options.INI settings refine the cursor itself:

Setting	What it does
`IMPROVED_NCTH_CURSOR`	`0` default cursor, `1` improved (extended AP info, laser dot, scope-mode icon), `2` compact (aim level as numbers, capped display sizes).
`ADDITIONAL_NCTH_CURSOR_INFO`	Extra target info shown while holding `Alt`: `0` none, `1` enemy armour, `2` armour, weapons and head gear.

Check a shot before you commit

Press F on a tile to get detailed information relative to the selected merc — cover, brightness, range, chance to hit, height and more. See the hotkey reference.

What affects your accuracy¶

Your merc and their condition¶

Every shot starts from a "Base CTH" determined by the shooter's skills — by default Experience Level counts three times as heavily as Marksmanship, Wisdom and Dexterity (BASE_EXP = 3.0 vs 1.0 for the others in CTHConstants.ini). The shooter's condition then modifies it: injuries, fatigue, low morale, being drunk, standing in gas without a mask, being bandaged, and — heavily — suppression shock all widen your aperture. A suppressed, wounded merc is barely able to shoot back effectively, which is exactly what suppressive fire is for.

Skill also sets a hard ceiling: the CTH cap, the minimum muzzle sway a merc can ever reach no matter how long they aim. Elite shooters can approach rock-steady aim; poor shooters always wobble.

Aim clicks¶

Right-click to add aim levels, exactly as under OCTH. The number of available aim levels depends on the gun. Two things are worth knowing:

Marksmanship is the primary stat governing how much sway each click removes (AIM_MARKS = 3.0).
Each successive click removes less sway than the previous one — by default the first aim click gives 8/36 of your total possible aiming bonus and the last gives just 1/36. At long range that final sliver can still be the difference between a guaranteed hit and a coin flip.

Stance and resting your weapon¶

Stance cuts both ways under NCTH:

Snapshots (no aim clicks) are easiest standing — it is hard to swing a gun quickly onto a target while lying on your belly.
Aimed shots are steadiest prone; crouched is in between.

In addition, a merc positioned behind suitable cover — tables, rocks, crates, open windows — can rest their weapon on it (WEAPON_RESTING = TRUE by default). This grants a crouching or standing merc half of the prone-stance steadiness bonus (WEAPON_RESTING_PRONE_BONI_PERCENTAGE = 50). Parking a shooter at a window ledge is one of the cheapest accuracy boosts in the game.

The gun itself¶

Each weapon's Accuracy value directly scales the maximum aperture — an inaccurate gun stays inaccurate no matter who fires it. On top of that, NCTH uses a "Gun Handling" concept based on how many APs the weapon costs to ready: heavy, cumbersome weapons are harder to snap onto a target, while pistols are quick. Firing one-handed, or a gun in each hand, multiplies the handling penalty. Attachments such as foregrips and stocks improve handling and autofire control — see the attachment system.

Sights, scopes and range brackets¶

NCTH divides engagement distances into brackets built on one number: NORMAL_SHOOTING_DISTANCE in CTHConstants.ini (default 70, measured in meters — 10 meters per tile, so 7 tiles). Iron sights are fully effective out to that distance; beyond it, accuracy starts to drop unless you have magnified optics:

A 2x scope negates the distance penalty out to twice the normal shooting distance, a 4x out to four times, a 10x out to ten times, and so on.
Scopes also have a minimum effective range (derived from their magnification via SCOPE_RANGE_MULTIPLIER). Aiming through a 10x scope at someone two tiles away incurs a hefty penalty (AIM_TOO_CLOSE_SCOPE) — high-power optics are for long range only.
How much of a scope's magnification a merc can exploit depends on their experience and marksmanship (SCOPE_EFFECTIVENESS_MULTIPLIER / SCOPE_EFFECTIVENESS_MINIMUM), and mercs with the Ranger, Marksman or Sniper traits get higher guaranteed minimums.

If a gun carries several sighting systems (for example a scope plus backup iron sights), press . or Q to cycle between scope modes and use the sight that matches the range (USE_SCOPE_MODES = TRUE by default).

Lasers¶

Laser aiming modules shrink the shooting aperture as long as the target is within the laser's range; beyond it they do nothing. The bonus is strongest in darkness, where the dot is easiest to see, and by default it is largest when firing unsighted/from the hip (LASER_PERFORMANCE_BONUS_HIP = 25.0 vs 15.0 over iron sights and 10.0 through a scope). That makes lasers the snapshot-and-night-fighting counterpart to scopes. Remember the laser can also give your position away.

Moving targets¶

Moving targets are harder to hit, and NCTH models it in some detail: the muzzle starts "behind" a moving target and shooter skill determines how well they track and lead it. Direction matters — a target running straight at you or away from you gives no penalty, while one crossing left-to-right gives the largest. Speed matters too, and in an unusual way: penalties grow with the distance the target moved, up to a point where the shooter "gets used to" the movement and starts compensating. All of this scales with range — hitting a runner up close is vastly easier than at distance.

Long range and bullet drop¶

Bullets in JA2 begin dropping to the ground once they pass the firing gun's maximum range. Under NCTH a skilled shooter (experience and wisdom) automatically raises the barrel when firing at targets beyond that range, buying up to roughly 15% extra effective range. Poor shooters get it wrong and plant rounds in the dirt — but even that can be useful for suppression.

Burst and autofire¶

NCTH replaces the old flat "CTH penalty per bullet" of burst fire with a physical recoil model. Each gun has a recoil pattern (typically up and slightly right) that moves the muzzle with every bullet. The shooter automatically fights it with counter-force: strength determines how much force they can apply, while experience, dexterity and wisdom determine how accurately and how often they can correct. A strong, skilled merc can walk a long burst back onto the target; a weak merc with a powerful gun watches the muzzle climb into the sky.

Practical consequences:

Give machine guns and powerful automatic rifles to strong, experienced mercs.
Tracer ammo gives the shooter an immediate extra chance to correct their aim mid-burst — mixed tracer belts genuinely help long volleys.
Recoil trouble scales with range: at twice the normal distance, recoil is twice as bad and corrections half as accurate. Keep autofire for short and medium range.
With USE_AIMED_BURST enabled in Ja2_Options.INI (current releases ship it on), you can add aim to burst and autofire with the mouse wheel, or , if the wheel is unavailable.

Even bullets that miss contribute suppression, so sustained autofire remains valuable far beyond its literal hit chance.

Why shots feel different from OCTH¶

Players switching from OCTH usually notice the following:

No more reliable percentages. The crosshair shows a spread, not a promise. Two identical-looking shots can land very differently.
Misses land near the target. Bullets fly through the game world, so near-misses chew up cover, suppress, and occasionally hit someone standing next to your actual target — friend or foe.
You burn far more ammunition, especially at range. Bring more magazines than you think you need. (CTHConstants.ini even has a BASIC_RELIABILITY_ODDS setting to compensate weapon wear for the higher round count.)
Range brackets rule the game. Without appropriate optics, long-range fire is mostly suppression. With them, a prone, rested sniper is devastating.
Close quarters are deadly for everyone: at short range even snapshots land, so positioning and interrupts matter more than ever.
Difficulty level matters: the base chance to hit under NCTH is one of the things scaled by difficulty (see Data-1.13\TableData\DifficultySettings.xml).

Turning NCTH on or off¶

NCTH is controlled by a single switch in Ja2_Options.INI (in the Data-1.13 folder), under [Tactical Gameplay Settings]:

; Play with New Chance to Hit System (NCTH)?
NCTH = FALSE

Set it to TRUE to play with NCTH, FALSE for the classic OCTH system. The setting applies to everyone in the game — your mercs, militia and the enemy alike.

On the old r7609 "stable" release this was a New Game screen option ("New Chance to Hit System"); the new-game screen was slimmed down starting with r8610, and NCTH itself moved into Ja2_Options.INI at r8625. See new game options for the other settings that moved. Current releases can also flip it without editing the INI: the 1.13 Features screen on the New Game screen has a "New Chance to Hit" toggle that can override the INI value (its Use These Overrides master switch must be on).

Pick one per campaign

OCTH and NCTH balance very differently, so decide which system you want before starting a campaign rather than flipping the switch midway.

Tuning NCTH: CTHConstants.ini¶

Everything about NCTH is tunable through CTHConstants.ini in the Data-1.13 folder. The file is heavily commented — every value explains what it does and its valid range. It is organized into four sections:

Section	Controls
`[General]`	The shooting mechanism as a whole: `NORMAL_SHOOTING_DISTANCE`, `DEGREES_MAXIMUM_APERTURE`, iron sight/laser performance, scope effectiveness, bullet gravity and range coefficients.
`[Base CTH]`	The "free" accuracy every shot gets: skill weights (`BASE_EXP`, `BASE_MARKS`, …) and condition modifiers (injury, fatigue, morale, drunkenness, suppression shock, gun handling per stance).
`[Aiming CTH]`	What aim clicks are worth: skill weights (`AIM_MARKS`, …), scope too-close penalties, condition modifiers while aiming.
`[Shooting Mechanism]`	Moving-target tracking and the autofire recoil/counter-force model.

For example, raising NORMAL_SHOOTING_DISTANCE makes everyone less accurate and scopes more important, while lowering DEGREES_MAXIMUM_APERTURE makes all shooting more accurate across the board. If NCTH feels too punishing (or too easy) for your taste, this file is the sanctioned way to fix that.

See the configuration overview for where the file lives and general INI editing advice, and the Ja2_Options.INI tour for the related gameplay switches.

Edit with care

Back up CTHConstants.ini before changing it, use a plain text editor, and respect the FLOAT/INTEGER notes in the comments — some values require a decimal point and some forbid it.

Practical aiming tips¶

Watch the crosshairs, not your instincts. Fire when the spread is close to the target's size; otherwise aim more or get closer.
Close the distance. The outer circle scales with range; ten tiles closer can turn a hopeful shot into a sure one.
Optics first. Once Bobby Ray's is available, 2x scopes for your rifles are one of the best early purchases you can make. Match magnification to the ranges you actually fight at, and switch scope modes (.) up close.
Before you have optics, fight at night and use lasers — the laser bonus is biggest in darkness.
Go prone and rest the weapon for deliberate shots; save standing snapshots for close encounters.
Use autofire and suppression freely. Missed bullets still pin the enemy down, and suppressed enemies shoot far worse at you.
Keep shooters healthy, rested and sober. Wounds, fatigue and drink all widen your spread — as does being suppressed yourself.
Repeat fire on the same target — a shooter firing again at the same, unmoved target gets a small accuracy bonus.
Bring more ammo than you would under OCTH. Seriously.
Consider a spotter for your snipers, and see the starter tips for more general early-game advice. Jargon unclear? Check the glossary.

Sources¶

New Chance To Hit — Jagged Alliance 1.13 HAM Wiki by Headrock (content verified via the Internet Archive snapshot)
CTHConstants.ini from the 1dot13/gamedir repository (current release data)
Ja2_Options.INI from the 1dot13/gamedir repository (NCTH switch, cursor options, weapon resting, scope modes, aimed burst)
Tactical/Weapons.cpp from the 1dot13/source repository (NCTH aperture calculation, iron-sight gradient and laser bonus behavior; fetched July 2026)
JA2_113_Hotkeys.pdf (r9389, 2022) — official 1.13 hotkey reference (keys cited here)
"Jagged Alliance 2 v1.13 — Starter Documentation" and "Play Guide" (2019, r8741 era) by tais & Yunotchi