Looking at the terrain types, the following can be considered:
- Steep Hills: Preferred as it is Bad Going, plus it allows your flanking light infantry to gain an advantage (uphill) should the enemy light infantry try to flank your battle line through the terrain.
- Gentle Hills: Not acceptable as it is not Bad Going, so virtually any fast moving elements can attack your flank and it will have an advantage (uphill).
- Woods: Preferred as it is Bad Going, plus it creates more of a command issue (extra PIP) for the attacking flanking force trying to outflank the battle line.
- Marsh: Acceptable as it is Bad Going, but it does not create a command issue as with Woods, nor an advantage for light infantry guarding the flanks. However, it might be upgraded to Preferred if the defending army protects the flanks with missile weapons. Note also that the shape of a Marsh can be "sausage-like".
- Rough: Rate the same as for a Marsh.
- Dunes: Rate the same as for a Woods, unless the attacking army has Camels. If the attacker has Camels and you defend the flank with Bows, rate it as Preferred, otherwise it is not acceptable.
- Oasis: Rate the same as for a Woods, unless the attacking army has Camels, in which case it is rated as not acceptable.
- BUA: This is a whole discussion unto itself and will be addressed in another blog entry.
- Waterway: Preferred as it is Impassable. A Littoral attacking army may use it to make a landing, so it is something that must be considered as to whether it is to be placed at all, but for the purposes of Anchoring Flanks, it works.
- River: 67% of the time a river will be useful for Anchoring Flanks and 33% of the time it will not. The problem is that you do not know which it will be until after you select it and the game has started. Consider it acceptable, especially in combination with a BUA.
- Road: Dangerous as it is essentially open ground and the enemy has the possibility of rapidly advancing upon your flank using road movement. Do not anchor a flank on a road.
- Arable: Waterway, Steep Hill, Woods, and River. A Gentle Hill or Road can be used, but should not be on the flank.
- Forest: Woods, Marsh, and River. A Gentle Hill can be used, but should not be on the flank.
- Hilly: Steep Hill, Woods, and River. A Road can be used, but should not be on the flank.
- Steppe: Rough and River. A Gentle Hill can be used, but should not be on the flank. Let's hope that if you have this topography you have an army that prefers not to Anchor Flanks!
- Dry: Steep Hill, Oasis, Dunes, and Rough. Pretty much every choice is a good one for an army that wants to Anchor Flanks.
- Tropical: Woods, Marsh or Rough, and River. A Road can be used, but should not be on the flank.
- Littoral: Waterway, Steep Hill, Woods, Dunes, Marsh, and River.
The 4 Point Defense
As the defender, the best way to ensure that your flanks are anchored when it comes time to deploy is to set up a "4 point defense" - or a board that has four defense points (in this case, terrain pieces). For example, see the figure below.
In the figure the green is the board (24" by 24") and the brown are terrain pieces (in this case the maximum 180mm x 180mm). The thin black line indicates exactly 40mm from the board edge, so with the terrain overlapping the lines, an element cannot pass between the board edge and the terrain piece; at some point it must pass through the terrain.
The "A" at the top of the screen is a reference point. If the board ends up being rotated by the attacker's choice of preferred baseline and the subsequent roll, the board configuration will essentially be the same no matter how the board is rotated, as shown in the figure below.
So, with the 4 point defense in place, your battle line can anchor it's flanks and the light troops can defend the terrain. The figure below shows how a defender (in blue) might utilize the setup.
In order to use the 4 point defense the defender's topography rating must have either preferred or acceptable terrain as one of the compulsory terrain types, given that you cannot choose four optional pieces of terrain and this defense requires four terrain pieces. So, returning to our Topography rating for the defender, what would the 4 point defense look like for each?
- Arable: A 4 point defense cannot be used as none of the compulsory terrain is ideal for anchoring flanks. (Exception: see the discussion on placing a BUA in a later blog entry.)
- Forest: Two Woods and two Marshes serve as the four points.
- Hilly: Two Steep Hills and two Woods serve as the four points as none of the compulsory terrain is ideal for anchoring flanks.
- Steppe: A 4 point defense cannot be used.
- Dry: For missile-oriented armies, or against armies that have Camels use two Steep Hills and two Roughs. Against missile-oriented armies use two Roughs and two Oasis.
- Tropical: Two Woods and two Marsh or Rough.
- Littoral: A 4 point defense cannot be used, as a Waterway is compulsory.