Artillery Fire Support in GOSS

Diving into Decision Games’ Grand Operational Simulation Series (GOSS) can be a hefty undertaking. In this series of articles, I chronicle my progress learning how to play the GOSS title Hurtgen: Hell’s Forest. In the last weeks, we took step by step the game apart starting with an introduction, followed by an overview of movement and mode rules, a look inside the box and the supply rules. It’s about time to get to the core of the rules.

Last time I described the procedure that would supply units with fuel and ammunition. Today I’ll give an overview of how to use those shells! We will go through the GOSS Fire Support rules, and more precisely GOSS Artillery Fire Support. Yes, there are procedures for Air Ground Support and Naval Fire Support, but those just differ in the way how the participating strength, expressed in Fire Support Points (FSP) is calculated. But I’m getting ahead of myself.

When Does Fire Support Happen?

We have seen already that GOSS can be rather procedural. The same is true for the execution of Fire Support.

Offensive, as well as defensive Fire Support, takes place during a game turn’s combat phase. As a reminder, here is the GOSS Sequence of Play:

  1. Air Allocation Phase (AM)
  2. Weather Determination Phase
  3. Command Phase (AM)
  4. Transport & Logistics Phase (AM)
  5. Allied Player Turn
    1. Allied Mode Determination Phase
    2. Allied Construction Phase
    3. Allied Movement Phase
    4. Axis Exploitation Phase
    5. Allied Combat Phase
    6. Allied Administration Phase
  6. Axis Player Turn (see above, reverse roles)
  7. Game Turn Complete

There’s one exception to this rule: Units in Exploit Mode may be subject to Air or Artillery Fire Support during the Exploitation Phase. The Fire Support procedure itself follows a particular order, the Fire Mission Sequence:

  1. offensive air support missions
  2. defensive artillery and air or naval support missions
  3. offensive artillery and naval support missions

A Little Bit of Math

There are four steps to be taken in each mission (Did I mention, Fire Support is very procedural?):

1. declare Fire Support mission

In order to shell the enemy, you need first to declare the Fire Support mission. For this, you select the target hex and a spotting unit. Only one Artillery mission per target hex per Combat Phase is allowed.

A good spotter is worth a lot. The size of the spotting unit determines the Fire Mission Capacity. A Light Fire Support uses a maximum of two/one artillery unit(s) (Allied/Axis) and can be carried by a company-sized spotter or no spotter at all. If you have a company-sized unit in a fortified hex or even a battalion-sized unit as a spotter, a Medium Fire Support can be deducted. A total of up to three/two (Allied/Axis) artillery units can participate in such a mission. You can bump this up to sixteen/twelve/eight (US only/Allied/Axis) units in a Heavy Fire Support Mission. Such a mission requires either a battalion-sized unit in a fortified hex or a battalion-sized unit in Prepared Assault Mode.

Artillery units will not participate willy-nilly in Medium or Heavy Fire Support Missions. At least one of them has to be subordinate to the spotter’s formation. Other units must be either assigned to the spotter’s formation. Army and Corps assets will need to be assigned to the the spotter’s Army or Corps, respectively.

2. calculate volleys and Die Roll Modifiers

Now off to the before-mentioned FSP. So what are those FSP? Like in almost any other game, everything starts with the Barrage Factors (see picture below).

Example of artillery and Fire Support capable units (M10).
The Barrage factors of artillery units can be found in the bottom left corner (The superscript indicates the range.). In scenarios after September 1, 1944, Tank Destroyers like the M10 can participate in Artillery Fire Support as well. Their barrage factors are equal to the number of their remaining steps. They have a fixed range of 4. On the German side, heavy AA guns can be used as artillery support.

The player conducting the mission will now assign the participating units. The sum of all Barrage Factors gives the total number of FSP (I guess the naming had to change to tie in Air and Naval Support. They do have Air Points and Naval FSP to derive their mission FSP).

For every eight FSP the player can conduct one artillery volley, e.g. 20 FSP result in three volleys, two full-strength ones and one with strength four. With sufficient ammunition in stock, an Intensive Fire Mission can be carried out. For each full-strength volley, a second full-strength volley can be fired if one Ammunition Point (AmP) is spent.

Finally, a Die Roll Modifier is calculated. The DRM is composed of cumulative DRMs for target hex terrain, defensive works, the amount of armor present, and the unit density in the target hex. The defensive player does not reveal the exact numbers of units in the target hex (fog of war), but will only announce the corresponding DRM.

The final DRM can’t exceed +/- 10.

3. determine result

Moral shock or casualties. The Fire Support Value Table.

With the DRM calculated, the player rolls a d10 for each volley and adds the DRM as well as the volley strength. The sum is the Fire Support Value (FSV). Consult the FSV table for the final result.

An AS (Artillery Shift) result represents the moral shock of the Fire Support. It will cause an unfavorable column shift in subsequent Ground Assaults. The AS status remains until the end of the current Combat Phase. A numerical result represents casualties inflicted by the Fire Support.

The results of all volleys (and Air and Naval Support missions) are summed up before being applied.

4. implement result

We will get back to those AS results when we talk about Ground Assaults. But how do the numerical results work?

Now, numerical results can be resolved by removing steps. Old school and simple. But if you look at the FSV table you will see that just the modifier for a full-strength volley (8) gives you already one AS. It’s not unthinkable to accumulate quite a few numerical hits over several volleys. At least enough to cause real damage. There are ways to ‘mitigate’ those hits.

Hits can be absorbed as Fatigue Hits, increasing a unit’s fatigue value by 1 (up to a maximum of 2). Fatigue represents the exhaustion of troops as well as stress on materiel. The higher the fatigue value the more limited a unit. To my mind a very interesting ansatz for a more continuous way to mark a losses due to ordnance.

Resolving artillery hits.
What to do when with all those hits after an artillery attack…

Units may choose to retreat by one hex. A retreating unit still will have to take one step loss. Remaining numerical hits are halved (rounded up), so n hits become 1 + (n-1)/2 hits. Btw. a retreating unit may violate stacking limits, this comes, of course, with all sorts of disadvantages, e.g. an increased unit density that will cause a higher Fire Support DRM in the new hex.

If units can’t retreat and have to stay in the target hex, hits can be partly absorbed by fortifications. For the remaining hits, the units will have to pass a Proficiency check. The result determines how the remaining hits are absorbed.

It’s important to note that a Maximum Step Loss rule applies in some cases. A unit can’t take more than one step loss per combat action. In cases when the rule does not apply, a second step loss can only be applied after all other units in the hex also lost a step.

Too complicated or too much to memorize? Don’t worry, a very handy priority list/decision tree helps to remember all those hit options.

And the Ammunition???

Why go through all the hassle of supply? Well, we saw already where we can spend AmP, namely during intense Fire Missions. But we also need to check whether units have sufficient ammunition left. After the first volley, the player rolls a d10 against the Corps’ Ammunition Depletion Value (ADV). The DR is modified if there’s more than one volley or if the supply path is extended. If the result is larger than the ADV the difference is the number of artillery units that are Ammunition Depleted (AD) (Be aware that American TD and German 88mm Flak units don’t check for depletion.). During an Intense Fire Support Mission, units are automatically AD, one for each added volley.

Units can be replenished during the Administrative Phase: one AmP can restock three units.

And just like this, our first Artillery Fire Support Mission is in the bag.

Final Thoughts

American soldiers service a 105mm howitzer in the Hurtgen Forest. (image source

Artillery Fire Support, you might get the impression, that it’s an awful lot, but it’s not. The player aids provide excellent check-lists that work perfectly as mnemonic device. Is it tedious? Not if you consider what you get in return a very nuanced simulation:

Artillery Fire Support is more than just accumulating enough barrage factors and then try to eliminate the opponent brut-force. Even if you get a viable spotter in position the number of artillery units you can use is capped. A total of n barrage factors will give you different odds for different targets in different hexes.

I like the implementation of the AS. Artillery Fire becomes a little less discrete (hit or no hit). Now there’s this additional effect that’s probably preferable to casualties but still describes an adverse effect.

Applying hits also becomes more than just removing steps. A full range of options from removing steps over retreating and removing less steps to add fatigue instead of step losses makes for a quite detailed simulation.

I understand that not everybody will feel the same about the Fire Support procedures in GOSS. Which is a good thing. Otherwise we would all play the same game, wouldn’t we? Let me know in the comments below, what your favorite game is concerning Artillery simulation. And if you are still curious and want to read more about Hurtgen: Hell’s Forest, come back next time when we conduct the first Ground Assault.

Abraços,
Carsten

Changelog:

  • 2020-02-25: American TD and German AA don’t require ADV checks or AmP for that matter (Thanks to Joey for pointing this out!).
  • 2020-02-25: Added that like American TD, German AA can act as artillery support as well (Thanks to Joey for pointing this out!).