Supply

Supply is a critical element in the effectiveness of any army, and so it is no different in armies you control in the Modern Campaign Series. There are two main functions of Supply. The first is how it influences the ability of HQ units to support their subordinate units. This point is explained and illustrated in the Command Section under the Command Test heading.

The second function Supply serves is to simulate the problem units in combat will encounter with becoming Low on Ammo or Fuel. When a unit fires during a turn, there is a chance that it will either run
Low on Ammo or, in the case of artillery units, become Unavailable in the next turn for that side. Likewise, when a unit moves or assaults, there is a chance that it will become Low on Fuel at the end of the day. These chances are based on the Supply Value for each side as displayed in the Terrain Info box of the Hex Info Area. Refer to the Main Program. This default Supply Value will apply to all units for that side unless the given scenario has Supply Source markers in use.


Global Supply Values

In each scenario, two Supply Values called the Global Supply Values are defined. These values, displayed in the Terrain Info Box as shown in the illustration, determine the default Supply Values for the Allied and Axis sides respectively. These values may vary, based on the calculation of Supply Variation and they may be superceded on the map by Supply Sources, both of which are described below.



Supply Sources

A Supply Source is a specific location that is capable of providing supply to units of the associated side. Axis Supply Sources are displayed on the map with a red marker as in the illustration while Allied Supply Sources are blue. With the Hot Spot on the Supply Source hex you can see in the Terrain Info box the owning side and value of the Supply Source.


In scenarios where Supply Sources are used, these values take precedence over that side’s Global Supply Value for non-naval units on the map. Where more than one Supply Source marker is present, units automatically use the highest Supply Source available to them. In the absence of Supply Sources, any map edge ground hex is essentially a Supply Source with that side’s Global Supply Value.


Supply Sources cannot be destroyed or used by the other side. Capturing an enemy Supply Source denies its use to the owning player while it is occupied.


Local Supply Values

At the beginning of each player turn, the Supply Value that applies to each hex containing friendly forces is calculated. This Supply Value is referred to as the Local Supply Value in that hex. It will be used to determine the state of Supply for all units in that hex. The Local Supply Value in Isolated hexes is 0 and thus not displayed.



Note: Local Supply Values are not needed after the beginning of the player turn and thus to save space are not saved in the battle file. If you open an existing battle file, the Local Supply Values will not be displayed until the next player turn.


Supply Determination

When supply issues are being resolved for a unit in a given hex, the Local Supply Value that applies to that hex is used. If there are no Supply Sources in the scenario for that side, then the Global Supply Value is used for this purpose. Otherwise, the Supply Source of highest value affecting that hex is used. If the unit is Isolated, then the Local Supply Value in the hex is 0. Otherwise, the unit must trace a line of communication (a line of hexes free of enemy units and their Zone of Control crossing rivers only using bridges or ferries) to any Supply Source hex or map edge ground hex when Supply Sources do not exist. In the absence of Supply Sources, any map edge ground hex is essentially a Supply Source with that side’s Global Supply Value. If there are Supply Sources used for that side in the scenario, then the unit must trace a line of communication to a Supply Source rather than ground edge hexes. When determining this line of communication, the presence of friendly units negates enemy Zones of Control.


Engineer Ferry Operations

When an engineer capable of ferrying units across a river exists, then supply can be traced across a river one hex if necessary to supply units that would otherwise be Isolated on the other side. The supply resulting from this only extends a distance of one hex from the engineer unit across the river hexside.


Isolated Units

Units that begin the turn Isolated have their morale reduced by one level. This morale effect is in addition to other morale reductions for such things as Low Ammo. Units that Fire while Isolated automatically become Low in Ammo at the start of the next turn. Artillery Units that fire while isolated become Unavailable. Units eligible for Low Fuel status that move while Isolated will automatically become Low Fuel on the following midnight turn. Furthermore, as long as the units remain Isolated, they will not recover from the Low Ammo, Unavailable, or Low Fuel effects.


Ammo Supply Problems

As stated above, when a unit fires during a turn, it becomes a candidate for either running Low On Ammo or, in the case of artillery units, becoming Unavailable in the next turn for that side. If a normal unit fires, then at the beginning of the next turn for that side a check is made to determine if the unit becomes Low On Ammo.

Isolated units automatically become Low On Ammo. Otherwise, a test is performed and a random value is generated and compared to the Local Supply Value. If the random number is less than the Local Supply Value, the unit passes the test and does not become Low On Ammo

If the unit fails the above test, a range test is made with respect to the unit and its controlling HQ unit. The HQ unit must not be Out of Command or the test will fail. Given that the HQ unit has a Command Range of C and that the range from the unit being tested to the HQ unit is R hexes, then the probability that the unit will not become Low On Ammo is C / (C + R).


The net effect of the above formula is that if a unit being checked for supply is at the limit of the Command Range, its probability of re-supply is 50%. For example, if an HQ unit has a command range of 7 and the unit under command of that HQ is 7 hexes away when the supply check is performed, then C=7 and R=7 and the formula would resolve that:


C / (C + R) = 7 / (7 + 7) = 7 / 14 = 50%.


Once a unit becomes Low On Ammo, then a determination is made for each turn for that side if the unit becomes re-supplied. For re-supply, only the range test described previously is used. Thus to be re-supplied, the unit must have an HQ unit that is not Out of Command.


For artillery units, the supply determination is different in that the range test does not apply. Artillery units become Unavailable based on the Local Supply Value of the hex they occupy. A random percentage value is generated and compared with the Local Supply Value in the hex. If the random value is less than the Local Supply Value the unit either does not become Unavailable, or if Unavailable already, loses that effect.


For naval units, half the default Global Supply Value for that side applies. Otherwise, the supply rules for naval units are the same as for artillery units.


Fuel Supply Problems

All non-Headquarters units other than Foot, Ski, Bicycle, Horse, Naval, and Rail units are subject to running Low On Fuel if they move or assault (for this purpose, changing Travel Mode or moving by Rail Mode is not considered movement). Once a day, at the beginning of the midnight turn, a Refueling Test is performed on every applicable unit that has moved or assaulted since the last time the test was performed. The test uses the supply rules that are used to determine Low On Ammo for units that fire with one exception. That is, Isolated units automatically become Low On Fuel, while units in supply first perform the supply test using their Local Supply Value, and a second test using a modified range test relative to their HQ unit. The distance traveled by the unit does not effect the outcome of the test. Failing the Refueling Test and becoming Low On Fuel represents a failure of the unit to obtain a refuel and thus being in a position of having to conserve available fuel until another refueling attempt can be made.


The range test to determine if a unit becomes Low On Fuel is passed provided:

  • The HQ of the unit is not Out of Command, and
  • The distance from the unit to the HQ is within the Command Radius of the HQ.

Once a unit becomes Low On Fuel, then two effects occur:

  • The movement allowance of the unit is cut in half. This represents the conservation efforts of the unit while under this condition.
  • The defense value of the unit is cut in half. This represents the reduced mobility of the unit due to the low fuel condition, making it more vulnerable in combat situations.

Note: when a Low On Fuel motorized or mechanized infantry is dismounted, it retains its default defense value and its default foot movement allowance.


Units that become Low On Fuel are eligible to regain their normal fuel status in two ways:

  • At the beginning of the next midnight turn another Refueling Test is performed. If the unit passes this test, then the unit is restored to normal fuel status.
  • At the beginning of each turn other than the midnight turn, a Refueling Test is performed, but with only a percentage chance of passing compared with a normal Refueling Test. The percentage used is the Refuel Percentage value determined by Parameter Data.

The first test represents the normally scheduled refueling that occurs each day, while the second test represents a refueling which occurs later because of a delay in the normal refueling. The supply test a unit uses to return to normal fuel status is a modified version of the test performed for units Low On Ammo. That is, the modified range test relative to the unit’s HQ is performed to determine if the unit is restored and the HQ unit must not be Out Of Command.


Helicopters

Helicopters that are Low Fuel or Low Ammo must land (ie, be in non-Travel Mode) before they are eligible for resupply.

Supply Variations

A scenario may have Supply Variations that affect the supply level for a particular side. There are two types of Supply Variations.

  • One-time variations can affect a scenario at most once, in which case they are deleted from the scenario.
  • Otherwise, a Supply Variation can affect a scenario multiple times.

The determination of whether a Supply Variation affects the scenario is done once per day, on the midnight turn or first turn after midnight, using the probability associated with the variation.

  • If the scenario has no Supply Sources for the affected side, then the variation affects the Global Supply Value for that side. Otherwise, the variation affects all Supply Sources for that side.
  • The resulting values are never modified below 0.
  • When Supply Sources are affected, then they can never be increased above the Global Supply Value for that side.

Supply Variations with probability 0 and a negative variation are triggered when the weather is Storm. Supply Variations with probability 0 and a positive variation are triggered when the Storm finishes.


Artillery Setup

When using the Artillery Setup Optional Rule, Allied and Axis Artillery availability depends upon the Artillery Setup value in the Parameter Data. An artillery unit capable of Indirect fire may not be available after it has moved. This represents that the artillery unit will have to setup the guns, bring up ammunition and re-establish communication links with the forward observers before it is ready for a fire mission. The length of time the artillery unit will be required to setup will vary depending on the Artillery Setup value in the Parameter Data. At the beginning of each turn for that side, for each artillery unit setting up, a random percentage value is generated and compared with the Artillery Setup value. If the random value is less than or equal to the setup value, then the artillery unit becomes available.


If the side has the Parameter set to 100%, then there is no setup effect for any artillery unit. If the Parameter value is at least 90%, then Self-Propelled artillery units are not affected by setup. Units can move, unlimber and be available to fire on the next turn or even the current turn if sufficient movement points remain.


If the side has the Parameter value less than 100%, then, as soon as an Artillery unit moves, it is labeled Setup Required. When the unit stops moving, there is a minimum one-turn delay. At the beginning of the next turn after a unit does not move or fire, there is a chance that the Artillery unit will be available, based on the Artillery Setup availability value. If the unit is not available on that turn, it will check again at the start of the next turn and each turn thereafter until it is available.


An Artillery Unit that is setting up can still engage enemy units using Direct Fire. In this way, artillery may move and still provide direct fire support. For example, if your artillery is setting up and enemy units break through your front lines, your Artillery units can still engage them by direct fire.


Artillery Setup does not affect Anti-tank guns and Anti-aircraft guns. Artillery units that start the game in Travel or Rail Mode and artillery units that arrive as reinforcements are deemed to have moved and will need to be setup before becoming available. Towed Artillery that is labeled Setup Required cannot become Setup while it is in Travel Mode.


Stockpiled Artillery

Stockpiled is a type of Artillery unit status that represents a battery in position with ample ammo at hand and effective communications in place. Therefore, such stockpiled units are deemed to be more effective.

Stockpiling can take place in one of two ways. A scenario designer can place some Artillery units in a stockpiled state at the beginning of a game. It may also be possible for a side to have the ability to stockpile during a game. This latter option depends upon the value of the Side Stockpiling percentage as seen in the Parameter Data. If this value is zero (0), no stockpiling can occur during the game for that side.


An artillery unit that is Stockpiled will be able to fire for longer periods of time,and perhaps with increased effectiveness, without suffering supply problems. In particular,

  • A Stockpiled artillery unit fires at an effectiveness modified by the Stockpiled Fire Parameter Data modifier. For example, if this modifier is 100%, then the fire value of Stockpiled units is not modified, but if the modifier is 200%, then the fire value of Stockpiled units is doubled.
  • When a Stockpiled artillery unit suffers its first supply test failure, it remains available, but loses its Stockpiled status at that point. Note: while Stockpiled, the supply test applied to a unit uses a supply value that is 75% of normal. For example, if the normal supply value is 80%, then the supply test applied to a Stockpiled unit uses 75% of 80%, equal to 60%, as the supply value for the test.

Provided that a side has a non-zero Stockpile probability in the Parameter Data, then Stockpiling occurs automatically under certain circumstances. In order for an artillery unit to be eligible for Stockpiling, it must not have moved or fired, must not be Disrupted or Broken, and must not have Unavailable status. Being in Travel or Rail Mode does not affect the ability to Stockpile. The test for Stockpiling only takes place during Day turns using the probability associated with that side. If the probability test succeeds, then the artillery unit is flagged as being Stockpiled. Any Stockpiled artillery unit losses its Stockpiled status if it moves, including by rail.


Supply Examples

Example 1: Command Test.

Suppose we have a Corps HQ with a command range of 12, a Divisional HQ, and that the base Supply Value is 70%.


2 hex range calculation: If the Div HQ is 2 hexes from the Corps HQ, then the probability that the Div HQ will be in command is:

0.70 + 0.30 * (12/14 * 0.70) = 88%


12 hex range calculation: If the Div HQ is 12 hexes from the Corps HQ, then the probability that the Div HQ will be in command is:

0.70 + 0.30 * (12/24 * 0.70) = 80%


Conclusion: In this case, an increase in the distance of the Div HQ from the Corps HQ by 10 hexes resulted in a decrease of its command probability from 88% to 80%.


Example 2: Refueling Test - High Value

Suppose that we have a Div HQ with a command range of 6 and a unit from this division that is Low On Fuel. Suppose that the base Supply Value is 80% and that the Refuel Percentage is 30%.


4 hex range calculation: If the unit is 8 hexes from its HQ, then the per-turn refuel probability is 0 since the unit is out of the command range of its HQ.


0 hex range calculation: If the unit is 4 hexes from its HQ, then the per-turn refuel probability is:

0.30 * 0.80 = 24%


Conclusion: You should move Low On Fuel units within the command range of their HQ for them to become refueled.


Example 3: Refueling Test - Low Value

Suppose that the situation is as before, but now that the base Supply Value is 25%.


If the unit is 4 hexes from its HQ, then the per-turn refuel probability is:

0.30 * 0.25 = 7.5%


Conclusion: Lower Supply Values mean less chance of refueling, in this case from 24% to 7.5% per turn.


Example 4: Refueling Test - Range Example

Suppose that we have the Corps HQ with command range of 12, the Div HQ with a command range of 6, a unit from the division that is Low On Fuel, and a base Supply Value of 60%.


4 hex and 12 hex range calculation: If the unit is 4 hexes from its Div HQ and the Div HQ is 12 hexes from its Corps HQ, then the per-turn refuel probability is:

0.30 * 0.80 = 24%


4 hex and 2 hex range calculation: If the unit is 4 hexes from its Div HQ and the Div HQ is 2 hexes from its Corps HQ, then the per-turn refuel probability is:

0.30 * 0.88 = 26.4%


Conclusion: Reducing ranges from units to their HQ and from HQ's to their higher HQ's improves the probability of refueling, in this case from 24% to 26.4%.


Summary

Here are some player tips for helping you understand the supply system better and to help you be more successful at playing the game.

  • Your HQ units and your base Supply Value (and Supply Sources depending on the scenario) will determine your supply state. Be sure in each scenario that you are aware of your base Supply Value and any Supply Sources on the map and their values. Understand which HQ units are strong or weak based on their command range and their quality rating. Understand your command hierarchy and which units are subordinate to which organizations.
  • Make sure you keep your units in the vicinity of their HQ (within the command radius of the HQ if possible). Likewise, pay attention to the distance between each HQ and its superior HQ as that will effect the ability of the superior HQ to provide support.
  • Be careful about leaving your HQ units in Travel Mode. This cuts their command range by 1/4. Consider taking HQ units out of Travel Mode as soon as you have established a position.
  • Be careful to avoid exposing your HQ units to enemy fire as a Disrupted HQ has its command range cut in half while a Broken HQ has no command range.
  • When you are in combat, Low Ammo problems will become more likely. When you are performing a breakthrough or racing to the defense of a position, expect to have more Low Fuel problems.
  • Consider regrouping at night and establishing a position with your units in proximity to their HQ and the HQ out of Travel Mode. This will give you the best chance of avoiding refueling problems during the midnight turn.
  • When Low Fuel problems develop, consider taking action that works towards solving the problems. This includes getting your HQ unit out of Travel Mode and returning your Low On Fuel units to within the command range of their HQ. You may also have to decide to withdraw an organization with severe supply problems so as to increase the support you get from the superior HQ.
  • Pressing on after Low On Fuel problems have developed during a breakthrough is a risky decision and combined with potential Low On Ammo problems that may arise after you make contact puts your forces at risk.
  • With Fog-Of-War in effect, you will not be able to explicitly see which enemy units have ammo or fuel problems, but if you understand what situations are likely to lead to such problems, you can use this to conclude good opportunities to try and take advantage of enemy supply problems.