HR.E.1: Pinning and Emergency Square Example #1(a) and (b). Much mis-interpretation of these rules have occurred. The following will clarify how the rules work. First, keep in mind the following published rules:
R. 1.1.3.1: Cavalry, infantry, and artillery are "combat units."
R. 8.2.5.1.1: No formation changes are allowed if touching or w/in 1" of an enemy combat unit.
R. 8.4: A unit is in "combat contact" when it actually touches, when attached to a unit that touches, or when an attached unit touches an enemy unit.
R. 8.4.4: Emergency Squares. When a cavalry unit moves into combat contact, an emergency square attempt must be made unless within 1" of another enemy infantry unit. (Per the "Blue Supplement" errata and clarifications, only infantry can "pin".) [NOTE: Rule 8.2.5.1.1 was never changed; therefore, it will be played as written and 8.4.4 is considered an exception. Therefore, a unit may not change formation if w/in 1" of an enemy combat unit (infantry, cavalry, or artillery) except that the unit may make an emergency square attempt unless an enemy infantry unit is w/in 1" (therefore, a unit may make an emergency square attempt even if w/in 1" of a cavalry or artillery unit but it cannot make any other type of formation change).]
R. 8.4.4.1: This merely describes the procedure: after the enemy cavalry unit declares it intends to move into combat contact (it must have the movement and space), when the cavalry unit is 1" away, the emergency square attempt roll is made. After the attempt, the cavalry must complete its movement to combat contact.
Example a: If an enemy cavalry unit moves to within 1", but not into combat contact of infantry unit X, no emergency square attempt is made. Moreover, unit X is not pinned; if another cavalry unit subsequently moves into combat contact with unit X, it would make an emergency square attempt. Unit X, however, cannot make another formation change (e.g., change into line) while the first enemy cavalry unit remains within 1" of unit X.
Example b: Assume enemy cavalry unit A has moved into combat contact with infantry unit X and unit X has failed its emergency square roll (there is no enemy infantry unit within 1" so unit X is not pinned). If another enemy cavalry unit subsequently moves into combat contact with unit X prior to the resolution of combat between units A and X (e.g., later in the movement phase or via a "breakthrough" attack), unit X will make another emergency square attempt (assuming no enemy infantry units are within 1" of unit X).
HR.E.2: Pinning and Emergency Square Example #2. Infantry unit X has artillery unit Y attached to its front. Enemy infantry unit A, positioned to the front of X and Y, moves to within 1" of Y (but not 1" of X). If enemy cavalry unit B moves to combat contact, unit X must make an emergency square attempt. Why? Rule 8.4.4 states that "an infantry unit(s) must make an emergency attempt to form square "unless the infantry unit is already touching or within 1" of another enemy infantry unit. . ." The rules make it clear that it is the infantry unit, and not any friendly attached artillery, that must be within 1" of an enemy infantry unit to be pinned. If enemy infantry unit A makes combat contact with artillery unit Y (which is attached to infantry unit X) before enemy cavalry unit B moves to combat contact, unit X would be pinned.
HR.E.3: Pinning and Emergency Squares Example #3(a) and (b). These examples illustrate HR.B.6 which prevents disordered infantry units from moving to pin enemy infantry units.
Example a: A disordered friendly infantry unit moves to within one inch of an enemy infantry unit and then a friendly cavalry unit makes combat contact with that enemy infantry unit. The enemy infantry unit is not pinned per R. 8.4.4 and will make an emergency square attempt.
Example b: A friendly infantry unit within one inch of an enemy infantry unit becomes disordered during the defensive fire phase. During the pursuit phase, a friendly cavalry unit makes combat contact with the enemy infantry unit. The enemy infantry unit is pinned per R. 8.4.4 and cannot make an emergency square attempt.
HR.E.4: Handling Units in Special Terrain. Much confusion and debate has arisen about a unit's location when it is partly in a terrain feature such as a town or woods. Keep in mind the following published rules:
R. 8.2.6.1.1: "Rough terrain is defined as any movement factor expenditure made while any portion of a unit or one of its bases is located in rough terrain."
R. 8.3.1: "Any unit located completely in a town always has cover against enemy fire."
R. 9.4.2.1-2: Any unit completely in a town or woods is in cover. Any unit in a gully, dry stream bed, sunken road, etc., is in cover unless the firing unit is at least partially located in the same terrain feature.
R. 10.3.4: If any part of a unit is in woods, the unit receives the noted combat modifier: (-5/-3/-2/-1 if cav/arty/inf/skirmish inf).
Based on these rules, any unit that is even partly located in rough terrain (e.g., woods, marsh, mud, etc.) is considered in that terrain for purposes of movement and combat. The unit does not receive the cover vs. firing unless completely in woods OR the infantry fire passes through the woods before hitting the unit (artillery fire that must pass through the woods to hit a unit partially in woods is blocked). If even partially in rough terrain, the unit will receive the combat modifier per R. 10.3.4 (e.g., even if only the back .01" of the unit is in the rough terrain). A unit that is only partly located in a town is not considered in the town for any purposes. Infantry or artillery fire on that unit would be blocked, however, if the town is between the firing and target units (see Rs. 9.2.3.1.1 and 9.2.3.2.1).
HR.E.5: Movement through Rough Terrain. See R. 8.2.6.1.1. A unit must move at it's rough terrain rate while any portion of the unit is located in rough terrain. For example, infantry unit X, in column (therefore, it has a depth of 2") with a RGH movement rate of 2/1, is moving through woods that is 1" deep. It will cost 6" to clear the rough terrain (i.e. to have the rear edge of the unit completely out of the rough terrain). Why? It costs 2" for the first 1" of the column to enter the woods (the first rank of bases), another 2" (total of 4") for the rear bases to enter the woods (the front bases exit the woods, but the unit is still considered in woods per Rs. 8.2.6.1.1 and 10.3.4), and finally, another 2" (total of 6") for the rear bases to completely exit the woods.
HR.E.6: Emergency Square Example #3(a) and (b). Per the Blue Supplement Errata, R. 8.4.4 also holds that an infantry unit may not make an emergency square attempt if the unit is in march column, located in a town, any type of woods, is holding entrenchments or a wall, and/or is routed.
Example a. Therefore, per the rules and illustrated by HR.E.3, if an infantry unit is even partially in a woods when combat contact is made by an enemy cavalry unit, it does not make and emergency square attempt. The infantry combats the cavalry in it's current formation (not "Sq v. Cav" unless in square-see R. 10.3.1.1.4) with the woods combat modifier noted in R. 10.3.4. The cavalry will fight the infantry in it's current formation modifier (and not "vs. OT"-see R. 10.3.1.1.5); if the cavalry is even partially in woods, it will also receive the woods combat modifier of "-5" (per R. 10.3.4).
Example b. If combat contact is made by an enemy cavalry unit when the infantry unit is only partially in a town, the infantry unit would make an emergency square attempt (unless in woods, pinned, etc.) and combat proceeds normally (note: the cavalry will not receive the "-3" modifier for attacking a town-see R. 10.3.10). Conversely, if the infantry unit is completely in the town (see HR.B.4, above), the infantry unit will not make an emergency square attempt. The infantry combats the cavalry in it's current formation (not "Sq v. Cav" unless in square; if deployed, it uses it's line formation modifier and receive's the town's combat bonus). The cavalry will fight the infantry in it's current formation modifier (and not "vs. OT"-see R. 10.3.1.1.5) and the cavalry will receive an additional "-3" for attacking the town.
HR.E.7: Moving Attached Artillery after Forming an Emergency Square. See R. 8.4.4.2. After a unit successfully forms an emergency square, attached artillery may be moved. The rules states that the artillery "may have their front facing adjusted . . . while maintaining contact." Therefore, the artillery unit may only pivot and, per the illustration (p. 15 of the Rule Book), it must keep at least part of its edge in contact with the same edge of the infantry unit it was in contact with prior to the infantry unit forming an emergency square.
HR.E.8: Commanding Generals. Many mistakes using attached leaders for rallying and modifying combats have been made (including by myself). Rule 1.1.4 makes clear that for an attached general to have any effect on the combat unit attached to (whether for rallying or modifying the combat), it must be the commanding general (i.e., the unit is in the general's chain of command). Therefore, if Division X's General is attached to a combat unit in Division Y, it cannot rally that unit. Furthermore, the general cannot add his combat modifier to that unit unless a combat unit from Division X is involved in the melee (see R. 10.3.1.2).
HR.E.9: Attached Generals. The following are several illustrations of what is permissible when a general is attached to a unit involved in combat.
a. The unit routs. Whenever a unit with an attached general routs, the attached general (after applying any effects from the leader casualty table, if applicable), is allowed to move anywhere up to his movement allowance.
b. Advancement after combat. A general attached to a unit that advances after combat must remain attached to that unit. If the general was attached to 2 or more units, it may remain attached to the other units if able to do so while still remaining attached to the advancing unit.
c. Cavalry recall. A general attached to a cavalry unit that fails it recall roll must accompany the cavalry's uncontrolled movement. A general attached to a cavalry unit that makes its recall roll may choose to accompany the cavalry or remain in place.
d. Cavalry bounce. A general attached to a cavalry unit that "bounces" must remain attached to the cavalry unit during its bounce move. The leader may attach himself to other units as long as he remains attached to the cavalry he "bounced" with.
HR.E.10: Units in Towns. Many mistakes and disputes concerning units in towns have occurred; these illustrate the rules as published. Keep in mind the following published rules:
R. 1.4.2.6.2: "To show that an artillery unit is deployed, it must be in or changed to unlimbered formation, and the base moved to face outward on the town . . . ."
R. 1.5: First, remember that artillery units are attached to infantry/cavalry units and not the other way around. Therefore when the rules say "attached to a unit that is deployed, " it refers to an artillery unit that is attached to either an infantry or cavalry unit.
R. 1.5.4: "To be attached to a deployed unit in a town, a unit must be completely in the town area. Units outside of but touching a town's perimeter are not attached to a unit deployed in the town." [NOTE: Per R. 1.5, this means that for an artillery unit to be attached to an infantry/cavalry unit deployed in a town, the artillery unit must be completely in the town. Because of this rule and R. 1.4.2.6.2, it is suggested that some system (markers or otherwise) be used to distinguish when an artillery unit is deployed in the town or is merely in a town.]
9.2.2.2: "Units . . . deployed in towns are considered to have their front facing in all directions, so their range may be measured from the center of any desired perimeter edge."
9.2.3: "EXCEPTION: A unit can always shoot at a unit in contact with its front face, regardless of the firing arc." [NOTE: this sentence is found in the Blue Scenario Book Errata.]
9.4.9 (as modified by HR.B.8): If a firing infantry unit is in square formation or a firing combat unit is deployed in a town, the die roll is modified by '-1'.
19.5.4.2: The firing player has the choice to use the (normal) Artillery Fire Template or the Spread Artillery Fire Template when firing deployed artillery units from towns or all-around fortifications.
19.5.4.3: "In all cases where a town or all-around fortification is involved in a combat contact, consider that an artillery and/or infantry unit deployed in there can always be fired at an enemy unit with which is in contact, even if the target unit does not fall in its normal firing arc."
Based on the rules (with the modification noted in R. 9.4.9), there are three possible situations when you have unlimbered artillery "touching" a town:
a. The artillery is deployed in a town: If an artillery unit moves completely within a town and unlimbers, the player may declare that the artillery is "deployed." The artillery is then moved with it's rear edge touching any one side of the building. The artillery may fire out of all four sides (regardless of where the gun model is), it may use either the "normal" or "spread" artillery fire template, it may fire at any enemy unit in combat contact with the town (regardless of where the gun model is), it receives a "-1" fire modifier (per R. 9.4.9), and combat is conducted normally;
b. The artillery is in the town but not deployed: If an artillery unit moves completely in a town and unlimbers and the player declares the gun " is not deployed," then the artillery is placed with it's rear base touching the town wall in the same direction as the gun's facing prior to unlimbering. The artillery unit may only use the normal artillery fire template, it does not receive a "-1" fire modifier (per modified R. 9.4.9), it may only fire at enemy combat units in combat contact with the side of the building that the artillery (not just the artillery base) is occupying, and combat is conducted normally.
c. The artillery is outside but "touching" a unit in the town: 1. If the unit (infantry or dismounted cavalry) in the town is deployed, then the artillery unit cannot be attached. The artillery may only use the normal artillery fire template (per. R. 9.2.3.2) and it does not receive a "-1" fire modifier (per modified R. 9.4.9). If the artillery unit is contacted, it fights the enemy alone (unless the enemy unit contacts both the artillery unit and the unit deployed in the town).
2. If the unit in the town is completely (see HR.E.4) in the town but not deployed, then the artillery remains attached to the unit, it uses the normal artillery fire template (per R. 9.2.3.2), it does not receive a "-1" fire modifier per (R. 9.4.9), and a combat contact with the artillery is conducted normally (i.e., the modifying unit will normally be the unit in the town; see HR.E.6(b) for examples of play when the attacking enemy is cavalry).