Wheeling Units in AMW

As I said in the Ilipa post I wrote an article about wheeling units in AMW for Slingshot. This is over 10 years old now, but I found it and it still makes sense to me. For those of you who never read it first time round, here it is:

Introduction

How much can units wheel or turn in good order? In many ways this question is almost as important in rule sets as the combat mechanism. It crystallises what the rule designer thinks about how historical armies manoeuvre. The less manoeuvrability the designer allows, the more the initial set up of the armies becomes important. Taking restrictions to extreme levels means after set up the game runs on auto pilot. Most designers aim for a balance between initial set up being important and allowing plays to react to what is going on.

Empirical data for how ancient armies turned is difficult to obtain. attempting to extrapolate from contemporary examples such as re-enactment groups or modern formal drill falls short for several reasons. For example, did ancient armies use cadenced step of any type? This is common to most modern mass manoeuvring by armies, but unlikely to have been used by ancient armies[1]. Secondly, the most troops you are likely to see in one place performing formal drill would be for the Trooping of the Colour. Interesting it may be – after all the lines are rarely absolutely straight - , but hardly comparable to a Macedonian phalanx with 5,000 men in it.

The rules for units turning in AMW are both delightfully simple and infuriatingly vague[2]. The rule says:

Turning. If a Warband, Auxiliary Infantry, Elephant, Heavy Infantry Heavy Archer, Heavy Chariot, Scythed Chariot or Heavy Cavalry unit wishes to deviate more than 30degrees from a straight line, it must use up half its movement allowance to do so,

i)    Light Infantry, Light Chariots and Light Cavalry may turn without penalty.

Looks easy, but what exactly does this mean? Neil has issued some clarifications, - for example all turning is by wheeling, plus units may perform a 90 degree turn to line up with an opponents flank, DBA style. His approach, - that games are played by consenting adults for fun as opposed to competition gamers aiming to extract every iota of advantage from overly precise rules – means that he is comfortable with a simple outline rule, allowing  reasonable chaps to fill in the gaps in needs be.

However, this rule leaves a lot of room for discussion and quite a few gaps to be filled in. I fear I am entering into territory that Neil didn’t consider when writing and play testing his rules.

Firstly I have to say that I am with Neil in that all turning should be by wheeling. Crab-like incline movements are difficult to order and achieve in a controlled way by massed units. The fact that Hoplite formations naturally deviate from the straight and narrow is irrelevant as this arises from the nature of the formation and is neither desired nor required.

About Face

Although it isn’t said explicitly, I think this is covered by the rule. I’d say that it is a deviation of greater than 30 degrees, and so takes half a move. That seems to me to be fair, and in line with what a lot of rule writers and wargamers expect. I think it is generally accepted by the players of AMW as well, so it can be safely left outside this discussion.

Wheeling

It is in respect of wheeling that I think I may part company from what the writer does in practice, and what players may want to see. However, I have tried to apply a logical, mathematical approach to the subject, in order to see where it gets us.

I haven’t played the game with Neil, but I’ve heard an account recently of how he managed a game on the SoA stand at a show, so I think I have a grip on what he actually does. As I understand it Neil allows the 30 degree wheel before the unit moves. So, for example, a Heavy Infantry unit wheels, and then moves a further 8cms.

For 90 degree wheel the unit would turn 90 degrees, then move 4cms, being the remaining half of its movement allowance.

All of this seems very fair and logical.  However, in practice both of these increase the movement speed of the wheeling unit considerably. This means units go faster when performing a complicated manoeuvre rather than moving in a straight line.

Let us assume that we are using 15mm figures on a standard 40mm bases, giving an 80mm frontage. If the unit is wheeling, then one corner remains in position, and the outer corner moves. For a 30 degree wheel we can calculate how far the outer figure goes before it commences its standard move, by the simple application of π. As you all remember from your geometry classes in school the circumference of a circle is calculated by 2πR, where R is the radius of the circle. As the unit has one corner pinned, and the outer corner moving the frontage of the unit is the radius of circle being described by the unit’s movement. i.e. The movement of the outer corner of the unit form part of the circumference of a circle, - in fact 30 degrees of the full 360. So, put simply, the outside of the unit moves 2 x 3.1416[3] x 80mm  x (30/360) = 41.88mm[4]. Let’s call it 40mm to keep it simple.

This means that our heavy infantry man on the outside of the unit now moves 12cm in the turn, - 4cm from the wheel, and 8cm of normal movement. In practice this means that if you want to charge a unit just outside of 8cm to your front then you can if you wheel first.

I can’t believe that is the intention of the rule.

The 90 degree wheel is more problematic. That gives a c12cm move distance for the outer man, to which a heavy foot unit would add 4cm for the remaining half of the movement allowance. That’s a total of 16cm, twice the normal move rate. Do the calculation for the 25mm figure bases and it gets even worse. I’ve done the sums for all the move distances for affected units in the tables below, using 15mm basing (NB Light units are unaffected, as they get to wheel for free anyway).

30 Degree Wheel Move Distances
Troop Type	Movement per turn	Wheel distance	Total	%age increase
Heavy Cavalry Heavy Chariots	20cm	4cm	24cm	20%
Elephant (one base)	12cm	2cm	14cm	17%
Warband, Auxiliary Infantry	12cm	4cm	16cm	33%
Heavy Infantry, Heavy Archers	8cm	4cm	12cm	50%

90 Degree Wheel Move Distances
Troop Type	Movement per turn	Wheel distance	Half Move	Total	%age increase
Heavy Cavalry Heavy Chariots	20cm	12.5cm	10cm	22.5cm	12.5%
Elephant (one base)	12cm	6cm	6cm	12cm	0%
Warband, Auxiliary Infantry	12cm	12.5cm	6cm	18.5cm	54%
Heavy Infantry, Heavy Archers	8cm	12.5cm	4cm	16.5cm	106.25%

Both these tables show that the wheeling rules distort movement distances, but they also throw up a bizarre effect. The elephant, which sits only one base wide, loses out compared to everyone else. Surely the narrower a unit, the faster it should wheel?

Is that what was intended? It may look okay on the table top, but it certainly isn’t logical.

A More Logical Approach

I take as my starting position the view that making large bodies of formed troops do anything other than move forwards and backwards in straight lines is very difficult. Lightly formed bodies are more flexible, but they still have issues when changing direction.

It is my conclusion after quite a few playtests that the movement that is part of the wheel should be deducted from the actual move distance allowed. For example, a heavy infantry unit can wheel 30 degrees, which takes 4cm. It can then move forward 4cm, being the residual amount of their move distance.

Wheeling over 30 degrees now becomes a more complicated calculation. If any wheel over 30 degrees means using half your movement allowance it implies that movement is at half speed. So, after the first 30 degree turn which takes 4cm, any subsequent increment of 30 degrees must take twice as long, - ie 8cm. This means that the maximum wheel per move varies by unit type. See table below

Maximum Wheeling Distance, 15mm figures on 40mm frontage bases (Heavy Units)
Troop Type	Movement per turn	30 degree wheel	Residual move	Extra wheels @ 8cm per 30 degrees	Total max wheel
Heavy Cavalry Heavy Chariots	20cm	4cm	16cm	60 degrees	90 degrees
Elephant (one base)	12cm	2cm	10cm	37.5 degrees	67.5 degrees
Warband, Auxiliary Infantry	12cm	4cm	8cm	30 degrees	60 degrees
Heavy Infantry, Heavy Archers	8cm	4cm	4cm	15 degrees	45 degrees

This seems to me to give a more reasonable feel to what is possible in a move. It increases the differentiation in unit manoeuvrability. With Heavy Infantry now taking two moves to turn through 90 degrees, Heavy Cavalry becomes the weapon you use to attack your opponent’s flanks.

Lights at the end of the tunnel.

I said above that light units were unaffected, because they get to wheel for free. However, they are not immune to the bonus move distances that the wheeling rules give them. See the tables below.

30 Degree Wheel Move Distances – Light Units
Troop Type	Movement per turn	Wheel distance	Total	%age increase
Light Cavalry Light Chariots	24cm	4cm	28cm	17%
Light Infantry	12cm	4cm	16cm	33%

90 Degree Wheel Move Distances – Light Units
Troop Type	Movement per turn	Wheel Distance	Total	%age increase
Light Cavalry, Light Chariots	24cm	12.5cm	36.5cm	52%
Light Infantry	12cm	12.5cm	24.5cm	104%

Some of these compare unfavourably to the move bonus Heavy Units are getting, especially Heavy Infantry. Even more reason to introduce a more logical approach to wheeling units.

If you apply the approach I have been arguing for above to light units, but don’t make the wheels after 30 degrees subject to the half speed suffered by heavy units, you end up with the following table for maximum wheels during a turn:

Maximum Wheeling Distance, 15mm figures on 40mm frontage bases (Light Units)
Troop Type	Movement per turn	30 degree wheel	Total max wheel
Light Cavalry, Light Chariots	24cm	4cm	180 degrees
Light Infantry	12cm	4cm	90 degrees

Light units come out of this slower than in the game as written, but relatively more effective compared to Heavy Units. Remember they can still about face for free, and now Light Cavalry are the only unit type that can wheel 90 degrees and still move. They also are now able to face the opposite direction and end up in a different place.

Conclusion

Whilst I’m not suggesting that the wheeling rules as written are broken, they do not stand up to detailed, logical examination. This may be the case for other rule sets such as DBA & DBM or even FoG, but I couldn’t say for definite. My experience of Armati is that it does not have this distorting affect and the wheeling rules are consistent. I just don’t like them very much.

The biggest problem the current rules would give you against a “gamey” opponent is the crabbed charge move for the likes of Heavy Infantry. By applying the approach I have given here that issue goes away, as wheeling move distances will now always be the same or less than the standard move distance for all unit types.

Of course, if you find the various adjustments to awkward to do in your head and you don’t want to cut up your copy of Slingshot and paste the tables above into your rule book there is a simpler way. Just don’t let heavy units wheel and charge into contact.

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[1] This is a moot point, with no hard evidence either way. I firmly believe that a phalanx must have marched in step in order to do any close combat manoeuvring. President Steele is immensely sceptical and holds a view tending more towards large crowd movement.

[2] There are four sets of similar rules in AMW, - Biblical, classical, Dark Ages & Medieval. This analysis uses the Classical rule set unit descriptions and attributes. The wheeling rule is common to all of the sets in AMW.

[3] 3.1416 is the value of  π, for those of you who were asleep in class that day.  The ancient Greeks actually used 22/7 in their sums, so I suppose you could use that instead to be more culturally relevant!

[4] For 25mm figures on 60mm bases the sum is 2 x 3.1416 x 120mm x (30/360) = 62.83mm.