Military units movement

[Mark_Everson]

Sounds OK, it gets the info across. Although I think my proposed solution is more aesthetically pleasing

[Gary Thomas]

I don't like the idea of separate colours for separate moves - it adds one more learning step to an already overburdened system.

As for showing the positions of the units at the end of the turn, that is not a bad idea, but I would make it a separate option, rather than automatic - otherwise there is the "has that one moved yet?" problem. Also, the red line track should only show for the currently selected unit, otherwise the scren will look like a red spider web - not at all aesthetically pleasing.

However, a button to show where the units are expected to be at the end of the turn (the enemy permitting) isn't a bad idea.

Cheers.

[Gary Thomas]

I am getting some odd effects from the movement system, which otherwise seems to be working, so I thought I should post the parameters I have used.

Units consist of a number of elements.

Each element has a category and a movement rate.

The movement rate is the movement in kms per day on a good road.

The category is (for land units) one of "foot", "horse" or "wheel" or "track".

The movement rate and category that I have used is:

Warrior	35 km/day	foot
HeavySpear	30 km/day	foot
LightSpear	35 km/day	foot
Skirmisher	40 km/day	foot
Charger	60 km/day	horse
CavalrySkirmisher	80 km/day	horse
Chariot	35 km/day	wheel

The slow speed for chariots arises because chariots were not used for transport outside of the battle field and so move at infantry speed.

Movement is arranged by "ticks", each tick is one tenth of a turn. If a turn is 30 dyas, then a tick is 3 days. Squares are 100km on a side, so it takes 100 / (3 * movement rate) ticks to move from one square to the next. The calculation multiplies diagonal move ticks by sqrt(2). Also the average of the source ticks and the destination ticks are used to indicate that half the time is spent in each square.

If a road exists (and none do in D5) this base tick time is used. Otherwise there is a terrain adjustment.

Terrain causes a multiplier to be applied to the ticks, as follows:

	foot	horse	wheel	track
Terrain:
flat	1.5	1.5	12.0	1.5
rolling	2.0	2.0	na	2.0
broken	3.0	5.0	na	6.0
massif	6.0	na	na	na
Cover:
crops	1.2	1.2	na	1.2
scrub	1.2	1.2	na	1.2
swamp	3.0	na	na	na
forest	1.2	4.0	na	4.0
jungle	1.2	na	na	na
dunes	3.0	2.0	na	3.0

Incidentally, if anyone can tell me how to get rid of the surplus blank lines before a table, I would be happy to hear.

Cheers

[Mark_Everson]

What you have looks good in general. I've got some suggestions for specific modifications, and will try to write them up when I get home from work. But for now... you never said what the problems were that you are encountering. Can you give a few examples of what you think are issues?

At a high level, I have one potential criticism. The flat and road movement rates are way too fast, at least for movement during actual warfare on 'the front' IMO. So your movement rates of something of order 10 squares per turn might be good for 'strategic' movement on roads safely within an empire, but not under conditions pertaining in a war zone. I think your quoted movement rates are acceptable assuming pre-positioned supplies, good knowledge of the terrain, and no need for advance scouting. Hopefully when modifiers for the lack of some or all of these are included the warfare movement rates will be more like the 200km or so per month that is all that is usually achievable in real historical campaigns. (using my best recollection of sources I'll try to cite later).

For one thing I think turns need to be of a length that TFs can only move a few squares under typical warfare conditions. That's because the idea of issuing orders that need to be appropriate throughout the turn without modification can't be successful unless things can't progress too far in an individual turn on the front. There was much discussion of this topic already in (IIRC) the 'lost' mil thread on the web site, and also the mil III thread.

[LDiCesare]

Do we have provision for uncontrolled terrain in the code?
Each square knows by which civ it is controlled, so we can add a multiplier for all squares whose controlling civ is not the army's civ, something like 10 seems a bit big but that looks like what would be needed to answer Mark's comments.

[Mark_Everson]

Hi Laurent:

Control of the square is only a small part of the factor of three or four reduction needed to get from what's in Gary's spec to what I think we need. As you say, it is easy to implement.

Gary:

BTW, the whitespace above tables is a mystery to me too. If it makes you feel any better, I've experienced it lots worse than what you have in your post above!

The other thing that bothered me in your generally excellent spec is chariots. Chariots could go cross-country successfully! At least for several types of terrain. As you have them, they're almost worthless. Remember that battles don't take place on roads themselves (too many people to fit on the road when deployed), and so to have any usefullness chariots Must be able to move over at least relatively flat ground. Keegan in 'A History of Warfare' refers to the 'cross-country chariot' (p165 in the paperback version). It "could be driven across rough ground". Chariots of this type were also used for hunting. IMO chariots should only have extreme trouble in heavy woods and on broken or mountainous ground. Your wheeled category is IMO probably too restrictive even for modern military trucks...

I couldn't find the text on rates of advance under contested circumstances (not necessarily active combat) but I think it was in the same book. If I come across the citation I'll let you know. But the most important point is, as I said above, that we have something like at most 2-3 squares of movement per turn under conditions of advancing in non-friendly terrain etc.

[Gary Thomas]

There is a book "Alexander the Great and the Logistics of the Macedonian Army" by Donald Engels, published by the University of California Press. Appendix 5 has a table which I summarize here (I include the mile figures because that is what is in the book, the km figures I calculated). In the original table each figure has a reference cited.

Location	Rate (m/day)/td>	Rate (km/day)	Units
Pelinna-Boetia	18.9(?)	30.4	whole army
Onchestus-Thebes	10.5	16.9	whole army
Therma(?)-Sestos	16.2	26.1	whole army
Arisbe-Percote	7	11.3	whole army
Percote-Praktios River	c. 11	17.7	whole army
Sardis-Ephesus	15	24.1	whole army
Gaza-Pelusium	19.5	31.4	whole army
Paraetonium-Ammon Oracle	22.5	36.2	small light force
Assyria	c. 46	74	cavalry only
Babylon-Susa	12.3	19.8	whole army
Ecbatana-Rhagae	22(?)	35.4	(1)
Rhagae-Airankief	34	54.7	(1)
Comisene	45 in c. 12hours	72.4	500 mounted infantry
Comisene	c. 33	53.1	(1)
Parthia	34.4	56.4	(2)
Sogdiana	c. 37.5-42.4	60.4-68.2	(3)
Sogdiana	43?-57.5	69.2-92.5	(4)
Mallian's territory	c. 30.6	49.2	(5)
Oreitan's territory to Pura	10.5-13?	16.9-20.9	(6)

The forces marked by (1) were:

• mounted scouts
• mercenary horse
• part of phalanx
• archers
• Agrianians

The forces marked by (2) were:

• mounted javelin men
• archers
• 2 phalanx brigades

The forces marked by (3) were:

• mounted javelin men
• 1 phalanx brigade
• regiment of bodyguard
• Agrianians
• 1/2 archers (not sure what this means)

The forces marked by (4) were:

• archers
• Agrianians
• lightest of phalanx

The forces marked by (5) were:

• archers
• Agrianians
• 1 brigade infantry Companions
• mounted archers
• 1/2 Companion cavalry

The forces marked by (6) were:

• whole army minus fleet and Craterus' force

These figures should be adjusted for the type of terrain. Also, Alexander used to bribe the officials in the next province to have magazines of supplies waiting for him, so had little in the way of supply problems, at least in the beginning.

The other thing that bothered me in your generally excellent spec is chariots. Chariots could go cross-country successfully! At least for several types of terrain. As you have them, they're almost worthless. Remember that battles don't take place on roads themselves (too many people to fit on the road when deployed), and so to have any usefullness chariots Must be able to move over at least relatively flat ground. Keegan in 'A History of Warfare' refers to the 'cross-country chariot' (p165 in the paperback version). It "could be driven across rough ground". Chariots of this type were also used for hunting. IMO chariots should only have extreme trouble in heavy woods and on broken or mountainous ground. Your wheeled category is IMO probably too restrictive even for modern military trucks...

You must understand that we are talking about 100km across open country, not a 200m charge in a battle. I suggest that you check this out by getting on a bicycle and riding 100 km across country, without using roads. Probably wouldn't be too bad on salt flats, but even on pasture land it would be impossible.

Chariots would fall apart if subjected to battlefield speeds for 100km.

As to the cross-country chariot, what was the context (I don't have Keegan's book, but have ordered it)?

The figures in my original table were not meant to be definitive - they were very much off-the-cuff figures so I could test the program.

I don't have any problem with adjusting them.

Cheers

[Mark_Everson]

Now That's a big white space!

The Keegan reference says little more than what I mentioned on the cross-country chariots. However he cites scholarship that says chariots were originally invented on the steppes... Not many roads there! Anyway, I don't want to debate this too much. Do it whichever way you think matches your sources for now, perhaps considering my input. If it turns out nobody ever builds chariots because of the limitations then we'll know you've limited them too much. During their day they were the equivalent of tanks and invaluable as is stressed in several books I've read.

The march figures Are impressive. Like you said, what you have is something to start with, and we can modify from there. I think just having to grub for food, as was frequently done, will slow them down to 2/3 or 1/2 ideal speed.

[Gary Thomas]

I think just having to grub for food, as was frequently done, will slow them down to 2/3 or 1/2 ideal speed.

I entirely agree. However, the march figures are, if you like, a best case. I see no reason for not having a "supplies multiplier" of around 3 for units that have to forage. This would get it close to the figures you wanted.

Cheers

[Gary Thomas]

The movement stuff is now working, and the combat stuff is working.

Now to get them to work together...

I have reread the material on economic versus military turns. Five year versus one month.

Can I assume that military moves start when a combat situation exists at the end of a turn (that is, the beginning of the next turn) and continue (one month at a time) until there are no combat situations, at which point the remainder of the current 5 year turn is assumed to take place?

Players should be able to give new orders at the end of each military turn. However, economic orders will not take effect until the end of the five year economic turn. This would prevent such things as building city walls as the enemy advanced toward the city.

Is this the way the model is supposed to work?

Cheers

[Mark_Everson]

Nope, you must have missed some critical posts... We discussed doing it the way you took it to be, but its very difficult and confusing. We do it basically as things are done in Civ, but with it a little more explicit what a turn means so that you don't think your unit is taking many lifetimes to get somewhere.

There is Only one kind of turn. But things happen at different Rates. One month worth of Military stuff always happens within a turn. However much more Economic, Technological etc. stuff than a month's worth can happen in a turn. At the start we currently think it should be about 5 years worth at the start of the game. (By contemporary times could be one season or one month.) It is only the Rate at which things happen as compared to the real world that differ between Military, Economic and the other models.

Some further discussion on this is here .

[Gary Thomas]

OK, I have checked out the reference. From the coding point of view it seems that there is one military move in each economic move. So it will take Alexander about ten years to get to Persia, just as in Civ. Is this right? It will not take much coding to arrange this.

Cheers

[Mark_Everson]

Yep, its that simple. But actually I consider the several turns it takes old Alex to get to Persia as just a few months. I just think I need a good slick explaination to players on how a turn is a month one way and several years another... Or we can just call it a turn and not try and associate a date with it...

[Gary Thomas]

I resist the temptation to reopen the issue. In checking all the posts I didn't see anybody suggest that the military and economic moves run separately and in parallel, meeting every so often when they coincide, in a system where, if there is no military activity (meaning actual combat) there are no military moves. Oh well...

Cheers

[Mark_Everson]

It was discussed. Reasons its bad IMO:

1. In Multiplayer when one player goes to war, everyone else gets bored stupid.

2. Unless you want the AI to play by different rules, then the finer-grained Military turns even in single player Always get run in many places since warefare is common. This takes many resources to do something the player doesn't see.

3. A month is roughly the right amount of time for the military turns to be as has been discussed above. You can multiply out yourself the number of monthly turns you'll get over about 3000-6000 years of history! Even assuming you're at war 1/3 of the time, its still a Lot of turns.