The primary result of any Suppressive Attack is to drain the target character's Action Points. Every other effect of Suppression Fire is based on this AP loss, and it is also the most effective use thereof.

History and Principles Edit

AP Loss was the driving force behind the JA2 Suppression System (which, unfortunately, was broken). Whenever a character came under suppression fire, he/she would lose some APs. Additional effects, such as Morale loss and Stance Drop, both result from AP loss.

The number of APs Lost in any attack is based upon the Suppression value of the attack (measured in Suppression Points), and the loss is mitigated by a third value called Suppression Tolerance which reflects a character's general resistance to Suppression.

The formula itself is somewhat complicated (see below), but is rather fine-tuned as is.

At the end of the Suppression Program, the character loses the designated amount of APs. Depending on the version of HAM you are using, this can push the character down to 0 APs or even less than that. If a character has reached a level lower than 20% of their initial APs this turn, they will begin losing APs off their next turn. In other words, they will start the next turn with less APs than normal.

Finally, in HAM 2.8 and above, AP Loss is used to calculate many new effects of suppression through the accumulation of Suppression Shock and all of its derivative effects. There is also reciprocal enhancement between the two, so excessive Suppression Shock may end up increasing AP Loss.

Why lose APs? Edit

The most important effect of real-world suppression fire is to block the enemy's ability to advance and/or retaliate. The enemy wastes its time trying to minimize the threat of being killed, instead of attacking and disabling the suppressor. Nothing represents this better than a loss of Action Points. Without sufficient APs, the character simply cannot act, achieving the suppressor's goal.

Problems with HAM B2.8 Edit

In JA2 1.13 (HAM B2.8), suppression fire could bring a character down to 0 APs. At this point, the character has lost 20% of the NEXT turn's APs. During the next turn, he can perform less actions than he normally, making him slower and therefore less dangerous.

However, HAM's original intention was to allow APs to drop below 0. The above was an artifact of JA2, when 0 APs were the absolute minimum. HAM failed to overcome this difficulty, and this failure was only discovered after HAM 2.8 was merged into the code.

When the lower AP limit is 0, then AP loss can only seriously affect characters who are being suppressed during their own turn (and not having had the chance to spend most of their APs), or characters who were saving some APs to increase their starting level during their next turn.

This works on a simple principle. You can spend up to 80% of your available APs without getting any sort of penalty in the next round. Every 1 AP you spend beyond this limit will come off your starting AP pool for the next round.

For example (100AP System):

Fidel has 23 APs at the start of each round. He spends 80% of these APs (18), remaining with 5 APs to spend this turn. His next turn is not yet affected.

Any extra AP that Fidel spends will count against his starting AP level in the next turn. If he drops 2 APs, his next turn will start with 21 APs. If he drops 5 APs (all the way to 0), he will start his next turn with only 18 APs (23-5=18).

Therefore, Suppression AP Loss was only important if the character had APs to spend at all. Suppression AP Loss can therefore be avoided by simply using up your action points each turn, when you expect to be suppressed during the enemy's turn. The AI does this notoriously often.

HAM 3 - Negative APs Edit

The solution was to allow Suppression Fire to push characters into NEGATIVE APs, making the impact on their next turn much more severe. This was actually implemented in earlier HAM versions, but was poorly written and did not work as desired.

HAM 3.1 fixed the problem, which turned out to be a piece of old code that frequently reset APs to 0 if they were negative. This code was altered, and now completely relies on the external INI setting that was originally supplied with HAM B2.8.

You can now set the lowest possible APs a character can have at any time, including negative values. Characters cannot voluntarily go under 0 by spending APs on actions. Only suppression and other AP penalties can reduce a character to negative values.

HAM defaults put this limit at -80 (100AP system) or -20 (25 AP system). When a character's Action Points reach this value, the character will start his next turn with 0 APs (sometimes even less!). This is called "being pinned down", and you will receive an on-screen message indicating this whenever it happens to a merc or an enemy. It is accompanied by a flashing radio locator over the character himself, in the tactical view.

The tactical implications are very profound. HAM Tactics allow you to make sure that an enemy is not going to fire back, while assaulters close the distance and eliminate him. Any sizeable chunk out of a character's APs can render them ineffective for a whole round, and is usually enough if it only prevented the particular enemy from firing back.

Mercs are as easily affected as enemies, of course, so it is important to be careful and not let a merc become too suppressed. Mercs need to cover each other, so that in the case of incoming suppression, a character isn't left undefended from enemy assaulters.

With experience, a soldier's Suppression Tolerance grows, diminishing AP Loss. Still, sufficient amounts of suppression fire on a single character has the potential to render him immobile, even at very high experience levels. It would simply require more firepower and ammo use on the part of the suppressors.

Calculating AP Loss Edit

The AP Loss formula has remained constant from JA2, as it was already sufficiently well-tuned. AP Loss is calculated from Suppression Points accumulated by the character, and are mitigated by the character's Suppression Tolerance value based mainly on Experience level.


AP Loss = ( ( (Suppression Points * "AP_SUPPRESSION_MOD" value) / (Tolerance + 6) ) * 2 + 1 ) / 2

The AP_SUPPRESSION_MOD value is an APBP Constant which changes automatically when using different AP systems.

Analysis of this formula gives the following graph:

Orig Supp Formula

Original Suppression Formula, using the 25AP system

Orig Supp Formula2

Original Suppression Formula, using the 100AP System

In this graph, the top (dark-blue) line is the graph at Suppression Tolerance 0.

The bottom (dark-grey) line is the graph at Suppression Tolerance 24.

You can see that high tolerance can severely reduce the AP loss to about 1/5 of the original value.

Please note that the amount of Suppression Points accumulated may vary, but on average a good 5-bullet Auto-fire volley is likely to generate around 18-25 Suppression Points to a character directly in its path.

Further effects of AP Loss Edit

AP Loss is used as a basis for measuring ALL other Suppression effects. Depending on the number of APs a character has lost, they will also lose morale, drop stance, and gain Suppression Shock. This is on top of the harsh implications of going to negative APs.

Therefore, AP Loss is really the most fundamental effect of Suppression Fire, as was intended in JA2.

Morale Loss Edit

As a result of losing APs, the suppressed character will also lose a proportional amount of morale.

This is done on a predetermined ratio between APs lost and Morale points lost. It's dictated by an APBP Constant called AP_LOST_PER_MORALE_DROP.


For every X APs the character loses to Suppression Fire, he also loses 1 morale point

X is the value of AP_LOST_PER_MORALE_DROP.

Stance Drop Edit

One of the more noticeable effects of Suppression Fire is that the target will attempt to drop a stance, from Standing to Crouching and/or from Crouching to Prone.

In the original JA2 Suppression System, the Stance Drop was actually beneficial to the TARGET. That's because once the character has dropped a stance, they are harder to hit, and ALSO get bonuses for being in a better shooting stance! Characters who go prone are also considered to be using their bipods... It makes you wonder what use there is for suppression fire if it only makes your enemies more powerful!

HAM's solution for this was to artificially reduce the suppressed target's accuracy (considerably!) through the application of Suppression Shock. However, the stance drop itself was left as it is, because it is the instinctive reaction of anyone under suppressive fire to seek the nearest cover, which usually is the ground itself.

Stance Drop can only occur if the character is losing enough APs for a stance change. If the cost to change from Standing to Crouching is 6 APs, then the character must lose that many APs in the current suppressive attack, if he is to drop a stance. The stance change is then COMPLETELY FREE.

You can drop all the way from Standing to Prone, given enough AP loss. Please note that the program checks whether the character can drop a stance at all in his current location. As you probably know, it is impossible to lie prone in some places, and also impossible to have any stance other than "standing" when in a water tile.

Characters also take nearby foes into account when considering a stance drop. If the nearest known enemy is too close (8 or less tiles away), the character will not drop below Crouching stance. This is reasonable, as going prone in close-quarters combat makes the person very vulnerable, so characters will normally not want to do this. However, characters who are Cowering (under massive Suppression Shock) will always drop a stance if they possibly can.

Suppression Shock Edit

Main Article: Suppression Shock

The second most important effect of Suppression Fire is Shock. This value is used to determine long-term effects, including accuracy loss and several other negative effects. Unlike AP Loss, Shock can linger on for several turns, being halved at the beginning of each turn. It will therefore disappear eventually, if the character can avoid further suppression fire.

Controlling Suppression Effectiveness through AP Loss Edit

Because AP Loss is the basis of calculation for all other effects, anything that increases or decreases AP Loss will invariably increase or decrease all other effects proportionally.

HAM has an INI setting dedicated to this purpose. It modifies AP Loss by a flat percentage, with the result being that Suppression becomes weaker or stronger as a whole. Using this setting, you can adjust the strength of all Suppressive Attacks to suit your personal playing taste.

Reducing AP Loss will make tactical combat resemble JA2 1.13 "vanilla" combat. On the other hand, increasing AP Loss can make suppression extremely powerful.

The default value, 100%, represents (hopefully) the best balance. It is the value where HAM Suppression is said to be "Fully Effective".

The value is also used to DISABLE suppression entirely, by setting it to 0. In such a case, AP Loss never occurs, and therefore Suppression has no effects at all.

Limits to possible AP Loss Edit

HAM offers settings for adjusting three different limits for AP Loss.

One setting limits AP Loss per Suppressive Attack. No single attack can cost more APs than this limit. A "single-attack" includes one auto-fire volley, one nearby explosion, or even a single aimed shot.

Another setting limits combined AP Loss per turn. It's used to limit the amount of suppression that can accumulate on a single character every turn, requiring more turns in order to fully suppress him.

The last setting, discussed earlier, controls the minimum number of APs a character can reach. When functional (HAM 3+), this is the lowest number of APs a character can EVER reach, through any means.

HAM Default limits are reasonably well defined, so they should not be tinkered with unless you know what you're trying to achieve.

Suppression Counter Edit

This is an artifact from JA2, and the source of the problem that broke the original Suppression System.

The Suppression Counter is a value which is used for keeping track of how many APs a character has lost so far this turn. This was later used in the formula to correctly convert Suppression Points into AP Loss.

The mathematic involving this counter are not terribly complex, but unfortunately they make little sense. It looked like they were not completed, or at least not thought all the way through. And in fact, it turns out that they really were not completed.

In JA2, the Suppression Counter was never cleared. Instead of recording how many APs have been lost so far this turn, it recorded how many APs were lost during the character's entire lifetime in the game. The result was that beyond a certain point, no amount of suppression fire could ever cause any AP Loss to the character, ever again.

HAM 2's solution was to clear the suppression counter when appropriate. It offers two methods - clearing the counter every turn, or clearing the counter at the end of every attack. The difference between the two methods is negligible, but this finally allowed Suppression to accumulate properly, opening the way to the HAM Suppression System.

HAM 3.5 - Stupid counter! Edit

During reconstruction work in HAM 3.5, it quickly became clear that the Suppression Counter was no longer necessary at all. It was removed from the code almost entirely, along with the INI setting that controls it. Good riddance!

INI Settings Edit

There are several settings that control Suppression AP Loss, in both JA2_Options.INI and APBPConstants.INI. This includes the setting that turns HAM Suppression on and off.

Please do not mess with any of these settings unless you fully understand what it will do.

1. JA2_Options.INI Settings:



Controls the potency of Suppression Fire by adjusting the number of APs Lost. Can also disable Suppression entirely.

Range 0 - 1000
JA2 Default Value 0

Suppression has no effect whatsoever.

HAM Recommended Value 100 Suppression is turned on to the default HAM level. AP Loss adheres to the original formula. This should provide a fun game which is nonetheless significantly different from JA2 in terms of tactical battles.
Other Values 50

Suppression is activated at "half-power". All AP Loss is halved. This is the midway point between JA2 Combat and HAM Combat.


Suppression is 50% stronger than the default. This is already enough to make suppression tactics brutal, and can make the game significantly more difficult to play.



Controls the exact timing at which the Suppression Counter is cleared.

Range 0, 1, 2
JA2 Default Value 0

The Suppression Counter is never cleared. This can have the effect of crippling the suppression system. It is NOT RECOMMENDED to use this value at all, even if suppression is turned off.

HAM Recommended Value 1 The Suppression Counter is cleared every turn.
Other Values 2

The Suppression Counter is cleared after each and every attack.

Notes This value is extremely complicated to explain, and should not be changed unless you're feeling adventurous.

ALSO: This value was removed in HAM 3.5 as it is no longer required at all.




Enabled/Disables a maximum limit on the Suppression AP Loss Per Turn / Per Attack. The actual limit is set with APBP Constants (see below).

HAM Recommended Value TRUE You can only lose a certain amount of APs per turn and per attack. This serves to make sure that teamwork is required to fully pin down enemies.
Notes The actual limits are set with APBP Constants (see below).

ALSO: Both values were removed in HAM 3.5 as they are no longer required at all.



Determines whether an on-screen message and flashing indicator show you which character has reached the minimum AP Loss possible. Suppressing this character any further will not cause any more AP Loss, but can cause extra suppression shock. These characters are "Pinned Down", and by default have lost their entire next turn.

JA2 Default Value FALSE

No indicator is shown on screen when characters are pinned down. You will have to estimate this yourself.

HAM Recommended Value TRUE A message and flashing indicator will show whenever a character has lost all the APs he can. Further suppression against this target will have no effect except increasing the target's Suppression Shock value.

2. APBPConstants.INI Settings:



Controls the ratio between Suppression Points and AP Loss.

HAM Recommended Value (100AP System) 24
HAM Recommended Value (25AP System) 6
Notes Do not mess with this value! If you wish to adjust the effectiveness of suppression fire, use the JA2_Options.INI Setting called "SUPPRESSION_EFFECTIVENESS" instead.



Controls the absolute minimum number of APs a character can have, ever.

HAM Recommended Value (100AP System) -80 A character can never have less than -80 APs. This is the amount of APs required to loss the entire next turn. There is no reason to go below it.
HAM Recommended Value (25AP System) -20 A character can never have less than -20 APs. This is the amount of APs required to loss the entire next turn. There is no reason to go below it.
Notes Changing these values can have a profound, often unwanted impact on the suppression system. Do not change this unless you know what you're trying to achieve.



Controls the ratio between AP Loss and Morale Loss.

HAM Recommended Value (100AP System) 12 For every 12 APs lost to Suppression Fire, a character loses one Morale Point.
HAM Recommended Value (25AP System) 3 For every 3 APs lost to Suppression Fire, a character loses one Morale Point.
Notes If you find that enemies flee the battle too often, or your own mercs become depressed too quickly, you can turn this value upwards. Conversely, if you want morale to drop whenever a character is suppressed, lower this value.



Sets the maximum number of APs a character can lose to Suppression Fire during the couse of a single turn.

HAM Recommended Value (100AP System) 200 A character can't lose more than 200 APs to suppression every turn.
HAM Recommended Value (25AP System) 50 A character can't lose more than 50 APs to suppression every turn.
Notes Do not mess with this value unless you know what you are trying to achieve!



Sets the maximum number of APs a character can lose in a single Suppressive Attack.

HAM Recommended Value (100 AP System) 64 A character can't lose more than 64 APs to any single suppressive attack. Multiple attacks can break this limit (see AP_MAX_TURN_SUPPRESSED)
HAM Recommended Value (25 AP System) 16 A character can't lose more than 16 APs to any single suppressive attack. Multiple attacks can break this limit (see AP_MAX_TURN_SUPPRESSED)
Notes Do not mess with this value unless you know what you are trying to achieve!

See Also Edit

Suppression Tolerance

Suppression Shock

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