Saturday, March 26, 2011

Hex War Games - Strategy Part IX - ZOC Defenses

Protecting a Target Hex
Since ZOC affects both movement and combat, it may be viewed as a type of ‘Terrain’.  Unlike most terrain, ZOC terrain moves around the map as the unit’s move.  The movement of a single unit with ZOC can greatly impact the mobility of the opposing army.  This article will discuss effects of various arrangements dealing with ZOCs.

For these examples, we will deal with the most common ZOC available:
  • Entering an enemy ZOC ends movement.
Additionally, a few other ground rules are necessary to establish:
  • Attacking and defending units are limited in number (no reinforcements),
  • The attacking units are attempting to reach the position(s) marked with an X,
  • All attacking and defending units may move a maximum of 4 hexes per turn,
  • For retreating purposes, the defending unit must retreat closer to the bottom of the map.
Defending Positions of a Hex
A unit may protect a given target hex three basic ways:

A – Preemptive Defense,
B – Last Ditch Defense,
C – Counter Attack Defense
Defense Positions

Some hexes may hold more than one type of defensive position depending on the Natural Terrain.  The diagram below shows a single attacking unit, the target hex, and the defensive positions in the surrounding hexes.

Preemptive Defense
The position marked ‘A’ is a purely preemptive defense.  Preemptive defenses have several advantages over the other types of defense.  Preemptive defenses require the enemy engage the defending unit before moving on to the objective hex, or taking extra time to bypass the unit.  For games which are timed, this is an excellent method of stretching the game out.  Even if the rules allow for “advance after combat”, the enemy unit may not take the objective location on this turn.

Bypassing the Preemptive Defense
If the game has retreat rules the defending unit may retreat to the objective hex due to combat results.  On the next turn, the unit is already in position for a Last Ditch Defense.  This may result in the enemy not moving on a subsequent round, again, controlling the flow of the enemy unit.

Preemptive Defense Retreat
A common drawback to the Preemptive Defense is the location of the hex “A”.  Usually the hexes where one would plant a preemptive Defense has the weakest Natural Terrain.  This is not so much a quirk of fate, as the reason the enemy is approaching from that direction in the first place.  If the objective were more readily reached from another direction, then the enemy would attack from that direction.  This means the defending unit in a Preemptive Defense receives no Defensive Bonus.  If this is the case, the defending unit may become a sacrificial unit, expected to simply delay the enemy.

Although the terrain bonus may not be the best, the Preemptive defense can be crucial when friendly units need two turns to move and engage the enemy.  This results in a Delaying Tactic may provide the time necessary for those forces to arrive and save the objective.

Last Ditch Defense
The ‘B’ marked on the objective identifies the Last Ditch Defense.  In this case, the enemy may march right up to the objective, but must fight the defending unit to take the objective.  Often times the objective hex has greater natural defensive advantages, so it seems reasonable to place a unit in Last Ditch Defense.  If sufficiently fortified, the enemy unit may spend turns besieging the hex before finally taking it.  Some games do provide the attacker bonuses to the attack based on the attacking terrain.  For these games, a Last Ditch Defense gives the attacker three options to attack from, and therefore some control over how the ensuing battle may end.

Last Ditch Defense and Retreat Positions
A danger does exist to the Last Ditch Defense if the game rules allow for Advance After Combat. In this case, if the enemy drives the defending unit out, the enemy may immediately take the objective hex.  If retreat rules are in place, the defender should end up in one of the hexes marked ‘C’.  They then find themselves in the position to counterattack on the following turns.

Counter Attack Defense
The positions marked ‘C’ are not designed to stop a unit from occupying the objective.  Instead, the unit launches a counter attack after the location is occupied.  This type of ‘defense’ usefulness occurs when the unit occupying the objective hex suffers a terrain penalty, such as tanks occupying a city.  The danger of such a defense is if the counter attack fails, the objective hex is left under the attacker's control.

Dual Defense Hexes
Positions marked ‘A/C’ may be either A or C type defenses depending on the natural terrain.  The opposing unit may avoid the zone of control of the defending unit, if the natural terrain allows quick movement for the opposing unit.  The movement is as follows:
Bypassing the Dual Space Defense Positions (A/C)
This defense is great if the natural terrain the attacker must travel to reach the objective prevents it from reaching it in one turn and the Natural Terrain in position A/C has greater defense bonuses than the hex in just position A.  Forests and rivers make great Natural Terrain limiters to movement.

Even if the defending unit is bypassed, the defender is now in a position to initiate a counter attack from its current hex.  If the defender is forced to retreat, the defender still finds itself in one of the original Counterattack Defense position.

Saturday, March 19, 2011

Hex War Games - Strategy Part VIII - Zone Of Control

Upcoming discussions will deal with Zones Of Control (ZOC).  This article will discuss several types of ZOC found in games.  I'm sure there are variations on these, so it is by no means inclusive of every possibility.  I've included some games I'm aware of for typical examples.

Zone Of Control
A unit's zone of control consists of the six hexes surrounding the unit.  Every game has differ combinations or rules regarding zone of control.  The degree of impact on the ZOC will differ for each game.  There are four areas of ZOC may affect:
  • Combat,
  • Movement,
  • Supply,
  • Command
Zones of Control can have multiple impacts on combat depending on the game.  I've categorized the most common as the following:
  • Passive - Units do not need to engage in combat
  • Active - Units must attack enemy units which end in their ZOC.  Alternately, some games declare that every opposing unit in the zoc of a friendly unit must be attacked, but not necessarily by the unit exerting the ZOC. (example: Artillery could count as an attack).
There are several forms of movement Zones of Control:
  • Interrupting: Units must end their movement upon entering the ZOC of an enemy unit.
  • Locking: Units may not leave a ZOC except through combat effects.
  • Fluid: Units may move through enemy ZOC, but at an increased movement cost.
  • Open: Unit has no ZOC effect on movement.
Supply & Command
ZOC may also affect supply and command of units.  The type of ZOC a unit may have is as follows:
  • Disrupting: Supply and/or Command lines may not pass through the ZOC of enemy units.
  • None: ZOC's have no impact on Supply and/or Command
Sample Games
Memoir'44 (or at BoardGameGeek)- Is a simple form of hex based war games.  I would classify it more in the Tactical category.  The units in this game effectively have a Passive, Open ZOC with no supply or Command limitations.  Effectively, every unit may move freely from one hex to another without penalty.  The only limitation is two units may not occupy the same location, so if blocking the lines of retreat more damage can be done on the unit.  It is a game with the simplest  form of ZOC available.

Weewar - A computer based Hex war game.  It has a Passive, Interrupting ZOC, there are no command or supply limitations in the game.  Units must end movement as soon as they end adjacent to an enemy unit, but they do not need make an attack.  One aspect of  the game which differs from others is that units exert ZOC against all other enemy units, even Sea and Air units.  In most games, Air units usually ignore ZOC effects.

A screenshot of a sample game is below.  The Blue Wheeled Unit (Raider) can normally move 4 hexes on plains terrain.  However, Red's units permit the Raider to move adjacent to them, but force the raider cease movement.  The shaded regions indicate areas where the Raider cannot move.
Interrupting ZOC from WeeWar
(Shaded areas cannot be reached)
Tac Air - Tac Air has one of the most restrictive ZOC I've seen in a game.  First, there are units representing supply and command units.  In the picture below, the NATO (Green) 2/35 unit is "In Command", but "Out of Supply" Since the ZOC from the 1/22 and 3/22 Pact (Brown) block the unit from getting to the supply unit.  The move was not without consequence, as the Pact's 1/22 unit is Out of Command, but In Supply.  Furthermore, since Tac Air has an Active Combat ZOC, both the 1/22 and 2/35 units must attack each other during the combat phase.

ZOC effects on Supply/Command from Tac Air
Russian Front - Russian Front is a great game covering the battles on, as the name implies, the Russian Front.  It also has one of the most unique ZOC rules I've encountered.  Unit's have a Fluid ZOC, it costs extra to movement points to enter hexes in enemy ZOC.  However, in order to engage in battle units must enter the same location as an enemy unit.  The tricky part is, once a unit is engaged in battle, it loses it ZOC.

This simple change means the Most Efficient defense does not protect as effectively.  Once an enemy unit moves into two friendly unit's location, the remainder of the enemy forces can flow in around them without hindrance.

Saturday, March 12, 2011

Hex War Games - Strategy Part VII - Bends In The Line

Bends in the line become inevitable as the battles develop.  Understanding how the bends affect combat can impact the defensive configuration chosen.  There are three basic configurations that permit bends in the line

  • V-Bend
  • A-Bend
  • Wave-Bend
A V-Bend consists of a single bend with the attacking force entering the inside "V" of the formation.  A benefit of this formation is it reduces the attacking force to a 1:1 ratio.  The weak point of this formation is the flanks.  It is usually necessary to place two strong defensive units as the anchor units.

V-Bend Formation
The A-Bend is the reverse of the A-Bend.  At first glance it appears to provide the same type of benefit as the V-Bend.
A-Bend Formation
In reality, the A-Bend formation suffers from a distinct disadvantage.  The lead unit can come under attack from three different directions.  This can eventually lead to a break in the unit which destroys the formation.
A-Bend Formation-Concentrated Fire
Since the first unit becomes the weak point in the formation, the lead unit usually requires the strongest unit lead the attack.  Another option for the attack is to have the middle units be the strongest available and the front unit being a sacrificial unit.  If the front unit is not sufficiently threatening, however, the defender can revert to the unit-to-unit attack.  It is critical to realize, if in a head-to-head fight, assaulting a V-Bend formation requires an A-Bend formation.

The Wave-Bend consists of an alternating V and A bends so the units form a "wave".  The major disadvantage to this arrangement is it provides no great benefit in either attack or defense.  Similarly, the formation needs to be attacked in a wave formation.  Usually this formation requires units alternate in strength, with the weaker units behind the stronger units.
Wave Formation

Saturday, March 5, 2011

Hex War Games - Strategy Part VI - Map Edge

Rarely in the world is the coastline hundreds of miles long and in a straight line.  There are even fewer places where forest, mountains or swamps transition right up to the sea.  In Hex Based war games, however, this seems to be the norm since every games has an edge, beyond which pieces cannot be attacked.  So, how can the map edge be used as an advantage, or disadvantage, to the pieces in the game.  We will discuss map edge effects in this article.

Map Edge Combat Effects
The edge of the board acts like a completely reinforced wall no unit may pass.  At most a unit may be attacked from four sides.  If forming a line along the grain, the board makes an excellent anchoring point.  Two configurations for anchoring on the edge exist:  On the Bulge or Off the Bulge.
Configurations for Anchoring on a Map Edge
When anchored Off The Bulge, some unit along the line may be attacked from two adjacent locations.  If anchoring the line On The Bulge, each unit may only be attacked a single time.  Thus, anchoring On The Bulge provides a better defense than Off The Bulge.

A final possible configuration is to have the line formed Off The bulge, but one unit jutting forward towards the enemy.  This creates a Bend in the line, but the addition of the unit allows the line to form On The Bulge and still reduce the attack to a 1-to-1 ratio.
Off The Bulge with an Advanced Unit