Why I think hills are horrible in wargames rules

Sometimes I get obsessed by tiny little aspects of the hobby and just have to write about it. In detail. A lot of detail, after endless hours of research. This time I’m picking on hills. You see hills were a thing in the South American Wars of Liberation – my current favourite period. A lot the battles featured at least one big hill e.g. Battle of Maipo. This hilly tendency could be extreme e.g. the Battle of Vargas Swamp was fought predominately on the slopes of a single giant hill and half the table top is covered in hills. Bolivar’s Very Bad Day, my Liberators variant of Tilly’s Very Bad Day, is going to have to cope with a lot of hills.

Unfortunately, hills are horrible in wargames rules. I’ve not seen any set of wargaming rules that cope with them really well, sadly, not even my own Tilly’s Very Bad Day. Certainly not my beloved Crossfire where hills are tiny mesas. I could have left it there, but I felt an obsessive urge to prove my claim of “horrible” so I got out a bunch of my wargaming rules, read the section on hills, and used a standard set of questions to test how well the rules handled hills. Here is what I found. It is horrible but there glimmers of genius.

Note: I’m talking about scatter terrain here, so hill features on a flat table top. I don’t consider contour lines possible in geo-hex and similar 3D terrain solutions.

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Hills in South America

Hills are a thing in the South American Wars of Liberation. As an example, here is my draft map of the Battle of Vargas Swamp. I’ve stripped out the irrelevant terrain and just left the hills. Roughly half the table is covered by hill features. Many are huge and all are steep. Given the Royalist defenders deployed across Picacho Hill and Cangrejo Hill this is going to be a game fought almost exclusively on hills.

There are lots of similar battles from the South American Wars of Liberation. The Peninsular War and Carlist Wars also feature massively contoured battlefields. The armies and battles of these wars are all, more of less, Napoleonics in nature, and Napoleonic generals sought out hills to give them a tactical advantage. That is exactly how Wellington won his battles.

I need rules that cater for these hilly table tops. During a game it must be clear when line of sight is blocked, when troops are uphill, and when overhead artillery fire is allowed. And equally important, the rules have to let me use the wargaming hills I already own.

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Questions about hills in wargaming rules

I’m sure many of you are perfectly happy with the way your preferred set of wargaming rules handles hills and that might mean you’re puzzled why I think wargaming rules treat hills horribly. I’ll try to explain with a set of questions.

My questions on hill rules are:

• Q1: What profile of hills are catered for?
  • Q1a: Are rounded hills with a single peak catered for?
  • Q1b: Are long hills with a ridge line catered for?
• Q2: What is line of sight across a hill feature
  • Q2a: What is line of sight across a complete hill feature
  • Q2b: What is line of sight across a dome, both peak and rounded slopes?
  • Q2c: What is line of sight across a ridge, both ridge line and rounded slopes at the end?
  • Q2d: What if a unit is shooting across the slope?
• Q3: When do units get the benefit of being uphill / upslope?
  • Q3a: What is the definition of uphill / upslope?
  • Q3b: What if two units are in melee across the slope?
  • Q3c: What if part of front edge is on the flat?
• Q4: What about overhead fire from a hill?

Wargaming rules treat hills horribly because they do not answer these questions adequately enough.

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The rules I looked at

These are the rules I looked at before writing this post:

• 2 by 2 Napoleonics
• Age of Gunpowder (AoG)
• Ancients D6 (AD6)
• Blitzkrieg Commander 4
• Blücher
• Crossfire
• DBA 2.2
• Division Commander II
• Field of Glory
• Impetus
• Lasalle II
• Napoleon at War
• One Hour Wargames – Horse and Musket
• Polemos English Civil War II
• Shako II
• Snappy Nappy
• Tilly’s Very Bad Day 2.0
• Volley & Bayonet
• Wargames Rules 1685 – 1845
• Warmaster Ancients

I own other rules. Lots of other rules. But after reading this set I got a good sense of the pattern of things.

You’ll notice quite a lot of Napoleonics in there but there are other periods represented as well.

I have gone through each of these and answered my hill questions. Rather than inflict that level of detail on you I’ve only summarised what I found for each question.

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Q1: What profile of hills are catered for?

Hills come in lots of shapes and sizes. But my wargaming hills are of only two types: domes and ridges. My names for them, “Dome” and “Ridge”, reflect the profile of the hill. Wargaming rules need to cater for the hills I actually have. [Remember my caveat above that I’m only concerned with scatter terrain and not for 3D solutions.]

Domes don’t have to be circular. Most of mine aren’t and I have circular, oval and even triangular domes. Ridges tend to be ovals but can also be other shapes.

For better or worse, most wargaming rules don’t talk about the profile of the hills (dome or ridge). The most common pattern in wargaming rules is to treat hills as blobs – they don’t care if the hill has a peak or a ridge line – the profile of the hill is irrelevant. A hill is a hill is a hill. Hills, the entire feature, block line of sight and there is no concept of uphill to a summit. Examples are: Age of Gunpowder (AoG), Ancients D6 (AD6), Crossfire and Napoleon at War.

[I call them “blobs” in this post but when playing Crossfire to often refer to hills as “mesa” where “a mesa is an isolated, flat-topped elevation, ridge or hill, which is bounded from all sides by steep escarpments and stands distinctly above a surrounding plain” (thanks Wikipedia).]

But there are rules that are more nuanced.

Q1a: Are rounded hills with a single peak catered for?

Dome: The majority of my wargaming hills are rounded with a single high point, the peak. I have round hills with peaks and oval hills with peaks. I even had triangular domes, e.g. the big hill from Battle of Maipo. I call this type domed because there is no obvious ridge line and the slopes curve away in nice rounded shapes. [Note: In common usage, a “peak” is pointy, but I call it a peak even if a technically minded hill walker would call it a “knob”, “crag”, “bald”, or “dome”.]

I suspect domes are the dominate shape for wargaming hills, but domes are a relatively rare occurrence in wargaming rules.

Breaking a trend towards ridges (see below), both Volley & Bayonet and Blitzkrieg Commander IV (BKC4) only have domes. Actually Blitzkrieg Commander IV calls them “high ground” not hills, but I know these are domes because the “centre of the high ground” is assumed to the peak.

Only two rules I found – Wargames Rules 1685 – 1845 and my own Tilly’s Very Bad Day – acknowledges domes in addition to ridges.

Wargames Rules 1685 – 1845 defines “Gentle hills all stand clear of the table edge, have rounded crests and smooth slopes” (p. 11). Sounds like my domes. The rules then describe hills with different footprints and profiles. Difficult hills include: Peninsular Hill, Finger Hill, Broken Ridge, Wooded Ridge, Steep Knoll. Gentle hills include: Long Ridge, Kidney Ridge, Short Ridge, Low Knoll. But all these types are either ridges or domes in my definition.

Q1b: Are long hills with a ridge line catered for?

Ridge: The ridge is the other type of wargaming hill I own. These features are long with a clearly defined ridge line at the summit. Most of my ridges are oval in shape, although I have a few which are odd shapes e.g. Gavilan Hill from the Battle of Gavilan which is more like a femur bone shape.

Those rules that do have hill profiles go for a predefined crest line that blocks line of sight, exactly what I call a ridge. DBA 2.2 is this type of game. All hills in DBA must have a “centre line crest”. This is a problem for me because I have a lot of domes and domes don’t have a “centre line crest”. You can draw arbitrary crests on a dome but that doesn’t really reflect their shape.

There are other problems with the “centre line crest” approach which I’ll cover below.

Only Wargames Rules 1685 – 1845 and my own Tilly’s Very Bad Day acknowledges both ridges and domes.

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Q2: What is line of sight across a hill

There are simple and more complicated rules for line of sight across a hill. Some of them relate to the whole hill feature (Q2a), some to domes (Q2b) and some to ridges (Q2c). There is also the question of shooting across the slope (Q2d)

Q2a: What is line of sight across a complete hill feature

For units on the flat, hills should block line of sight and hence direct fire.

As I mentioned before, most wargaming rules treat a hill as a whole as blocking terrain. So there is no summit/crest/ridge/peak. Age of Gunpowder (AoG) and Ancients D6 (AD6) are examples of this approach, as is Crossfire.

As a bit of an outlier, I discovered that although other terrain blocks line of sight in 2 by 2 Napoleonics, hills do not. Ooops, probably an oversight by the authors.

However, some rules are more nuanced and block line of sight at the summit or an implicit crest.

Q2b: What is line of sight across a dome, both peak and rounded slopes?

Line of sight should be blocked where it crosses the body of a hill. Typically this is related to where the summit of the hill is. Direct fire units can shoot up to the summit but not beyond.

As I mentioned, few rules cater for domes with a single peak and slopes falling away from the peak. I only found four.

In Tilly’s Very Bad Day both the peak of a dome and ridge lines block line of sight:

In addition to hills being blocking terrain as a whole, hill crests are also blocking terrain for units on different sides of the crest. A crest is the peak of a hill or defined ridge line. All hills have a peak. Only some hills have a defined ridge line. If any part of a unit is beyond the peak then the whole unit is assumed be beyond the peak. The entire unit must be beyond a ridge line for it to be blocking terrain.

Both Volley & Bayonet and Blitzkrieg Commander IV (BKC4) also talks about “crests”. These are not pre-determined but calculated during the game based on the relative position of the observer and the centre of the hill. In my language, these systems treat every hill as a dome, with the centre of the hill feature as the peak, and then determine implicit crests during play based on some simple geometry. The two systems use different language but the rule is the same I’ll reproduce them here:

This is the V&B version:

Each hill is assumed to have a crest line, which runs down the centre of the hill perpendicular to the line of sight [facing] of a unit. The crest line is the point at which the line of sight of a stand on a lower elevation is blocked. (p. 32)

And for BKC4:

To determine LOS to and from high ground, calculate the crest-line of the terrain feature as and when required during the game. To do this, draw an imaginary line across the centre of the high ground, parallel to the front base edge of the unit on lower ground. This line will be the crest line in relation to that unit, with any troops forward of the line being within LOS, and those behind it bing out of sight. (p. 14)

In V&B the implicit crest is perpendicular to the facing of the unit and in BKC4 the crest is parallel to the front edge of the unit. Same, same. Enemy are visible on the slope rising up to the implicit crest and hidden on the dropping slope on the far side of the implicit crest. This is what that looks like.

In the example:

• Blue 1 cannot see Red 1 over the small circular dome.
• Blue 2 can see Red 2 as the red cavalry is on the rising slope of the small oval dome.
• Blue 3 cannot see Red 3 because it is on the far side of the small oval dome.
• Blue 4 cannot see Red 4 behind the large oval dome.
• Blue 5 can see Red 5.

That is a pretty clever rule but it is open to exploitation. Simply by pivoting a unit you can open up the rear of a hill to sight.

Admittedly if the rules only allow direct fire to the front, which is true for both V&B and BKC4, then this is probably okay. But in a rule set like Crossfire, where direct fire is possible in a 360 degree arc, then this loop hole would need to be filled.

Despite that caveat I think the implicit crest line concept is pretty cool.

Q2c: What is line of sight across a ridge, both ridge line and rounded slopes at the end?

My ridges have a ridge line and rounded slopes at the end.

A significant minority of rules demand predefined crests on the hill features with line of sight is blocked at the crest. In my language these are ridges. DBA 2.2, Blücher and Lasalle all follow this pattern. For example, Blücher says “it is important for players to be clear at the outset of a game where the crest line of each hill is located.” The implication is the crest spans the length of the feature.

These predefined cess block line of sight.

Predefined crest lines is an easy and sensible approach, but I have three problems with it.

My first problem is that not all wargaming hills have a crest line. The insistence on predefined crest lines means my ridges are catered for (yay!) but my domes are not (boo!). It is artificial to impose a predefined crest on a dome. As you can see from the illustration below a dome there are an infinity of lines that cut across the hill, through the peak. None of them are better options than the others for the predefined crest line. Once you choose one, things start getting weird.

The second problem is the implication is that if the line of sight does not cross a predefined crest line, then it is not blocked. this leads to some weird situations with units shooting the length of a long ridge or across the slopes of a dome. Silly. Admittedly this would be addressed if the whole feature blocks separately from the predefined crest line but the rules don’t.

Lastly, this approach doesn’t cater for the rounded slopes at the end of the ridge (or the all round rounded slopes of a dome). My ridge features have these curved slopes at each end and it is unclear what happens when units are righting on these curved slopes rather than across the ridge line.

None of the rules address these problems, but the same three come close.

Volley & Bayonet and Blitzkrieg Commander IV (BKC4) ignore the ridge line and treat the centre of the hill as a peak. The rounded slopes are well catered for although the geometry can get a bit odd with long ovals. Of course these hills don’t acknowledge the ridge line, which is a problem.

Tilly’s Very Bad Day explicitly addresses ridges lines but does less well on the rounded slopes at the end.

Q2d: What if a unit is shooting across the slope?

I’ve done a fair bit of hiking and visibility across a hill slope is often not great with unexpected dips and rises. Undulations that are only visible when you get to them. You’re more likely to be able to see people on a nearby hill, across a valley, than people on the feature on which you are standing. Perhaps visibility should be limited on a hill.

So I asked myself, do wargaming rules limit visibility across the slopes of a hill because of undulations that are not otherwise represented? Well, no, wargaming rules don’t do this. Line of sight is either blocked by the entire feature, a predefined crest line, or in two cases an implicit crest line based on relative positions. Is this good enough?

Starting with the implicit crest lines, Volley & Bayonet and Blitzkrieg Commander IV (BKC4) limit visibility in interesting an unexpected ways for two units shooting at each other across the slopes of a hill.

The rules that rely on predefined crests don’t limit range on hills. Rather than look at all of the rules, which share the same problem, I’ll only look at DBA 2.2. Although my Tilly’s Very Bad Day also allows for domes with peaks, I’ll also look at them because they share behaviour with DBA.

In DBA 2.2 bows shoot 200 paces. For most people is 200 paces is 50mm on table with 40mm wide units. A DBA hill must “fit inside a rectangle, the length plus width of which totals no more than 9 element base widths… features cannot be less than 1 element base width across in any direction” (p. 6). The smallest circular dome is 40mm across and the largest circular dome is 180mm across. The biggest oval hill would be 240mm long and 120mm because a 2:1 length to width limitation applies. These dimensions mean a DBA bow unit cannot fire very far across a large hill but can fire across the smallest DBA hill. That is probably why, with more than 30 years of experience playing DBA, I’ve never thought “oh, gosh, my bow can shoot too far on that hill.”

My own Tilly’s Very Bad Day is more generous. Shot fire 4 TUM (Tilly Unit of Measure, which is half a base width). Assuming a 40mm wide DBx base, this gives shot a range of 80mm. Small hills are also 3-4 TUM across (60-80mm), medium are 4-6 TUM (80-120mm) across and larger are 6-8 TUM (120-160mm). So my shot units can also fire across a small hill but they can shoot half way across a large hill. But with five years of play with Tilly’s Very Bad Day, that hasn’t caused a weird situation.

On balance I suspect relatively short shooting ranges, combined with the limitations provided by the summit of a hill, limit the more extreme excesses of shooting across slopes, at least for bows and muskets.

In contrast to bows and shot, artillery might have a problem. In DBA 2.2 artillery shoot 500 paces (125mm) and in Tilly’s Very Bad Day artillery have unlimited range. You’d think that would cause a problem, but we’ve not seen any issues, even though every battle of TVBD includes artillery on both sides.

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Q3: When do units get the benefit of being uphill / upslope?

Many rules give some troops an advantage in melee when uphill / upslope. Do these rules make it clear what uphill / upslope means or do they assume it is obvious? I ask this question because, in some situations, being upslope really isn’t obvious. This is why have the edge case questions below.

Rules that treat hills as blobs don’t have a problem. Both units are on the hill. Personally, for some periods, I think fighting up a hill should be simulated. So the blob approach doesn’t really work for me for these periods and I’ll generally focus on other rule systems.

Q3a: What is the definition of uphill / upslope?

Unfortunately, most rules that give a combat advantage for being uphill fail to define what that means. This vague “uphill” shifts the burden of responsibility to players to decide. My experience is that when players get to decide anything in a game, they argue about it.

I’ll pick on Shako II as the example, it says “Infantry Battalions that are stationary defending uphill … receive a +1” in melee. But Shako doesn’t explain what uphill means. Truth to tell Shako II is no better or worse than most of its counterparts.

Napoleon at War (NaW) and Snappy Nappy get around the whole uphill problem by giving combat advantages to any defending unit on a hill. So whether it is uphill, downhill or across the slope, a defending unit will get significant combat advantages. This approach is clear but I would prefer something that acknowledges where the top of the hill is. The author of Snappy Nappy seems to have felt the same way, because he breaks the purity of this solution by giving an even bigger melee advantage to units defending a “Hillcrest” … a term he doesn’t mention anywhere else in the rules.

One Hour Wargames (OHW) gets around the problem a different way. A defending unit only gets the melee advantage if it is on the top of the hill: “If the defending unit occupies a hilltop, it only suffers half the indicated number of hits (rounded any fractions in favour of the attacker)”. The requirement to be on the “hilltop” removes the need for a definition of “uphill”. But that doesn’t really work for the giant hills I’ve got in mind.

DBA 2.2. tries to be more explicit about uphill: “All hills slope up to a centre line crest and give a close combat advantage if part of an element’s front edge is upslope of all of its’s opponents”. I give the authors points for trying, but it was this definition that made me write this post because it invites lot of questions e.g. fighting across the slope and with part of the unit on the flat.

In hindsight, I now think my own Tilly’s Very Bad Day is no better than DBA. Units charging uphill at infantry are disadvantaged but all I say about “uphill” is “use the centre of the units involved to determine which unit counts as being uphill”. This exposes TVBD to the same nasty edge cases as DBA.

Impetus I think does it slightly better than both DBA and TVBD. Impetus only rewards units that are “highest on a ‘gentle’ hill” (steep hills give no benefit in Impetus, which I think is unfair). Highest means “whomever is facing downhill with their front closest to the crest or middle of the hill”. I quite like that “facing downhill” as it partially addresses the across the slope problem of the edge case questions below.

Q3b: What if two units are in melee across the slope?

Now we get into the tricky edge cases. Only rules which give a combat advantage to being uphill need to worry about units fighting across a slope. How do they handle it?

In the example about, the units are in melee on the slopes of the hill. Which of them is upslope? This is my huge bugbear with wargaming rules or perhaps with wargamers. When we have two units fighting across the slope of a hill, one player will always argue they get the uphill / upslope bonus. I think that is ridiculous.

The definition of uphill in DBA 2.2 would give the advantage to the blue infantry on the circular hill and the red cavalry on the ridge. But you’d have use micro measurements to prove it. Personally I think that is too generous. I’d give none of the units the uphill advantage.

Impetus might exclude these examples because none of the unit are “facing downhill”

Q3c: What if part of front edge is on the flat?

How much of a unit has to be on the hill to count as on the hill? Any part, the majority, or all? I lean towards majority or all.

In the illustration I wouldn’t give either blue unit the advantage of uphill / upslope.

On the circular hill the blue infantry has only a small part of the front edge on the hill with the majority of the front edge on the flat. I would count these as on the flat. DBA 2.2 has them fighting on the hill.

The ridge has an extreme case. In one game my opponent charged his unit (blue infantry) down a hill and onto the flat to contact my unit (red cavalry). He argued he should get the uphill / upslope melee bonus because his blue unit had charged downhill and were still (partially) on the hill whereas the enemy were clearly not uphill. I thought it ridiculous then, and I still do. These units are fighting on the flat. Luckily DBA 2.2 agrees with me.

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Q4: What about overhead fire from a hill?

Players love overhead fire from a hill. Particularly by cannon. So it is guaranteed if there is a cannon and a hill, one of the players will ask, “can my gun fire over my own units if I put it on the hill?” There are historical instances of overhead fire, including by cannon and more recently by heavy machine guns. So it is a reasonable question. But not all period or rules should allow overhead fire. In fact I only found two rule sets that mentioned fire from hills.

AD6 lets a unit on a hill shoot at a unit on another hill.

Division Commander allows overhead fire.

A firing unit on a higher elevation can fire at a target unit that is behind an intervening unit if the target is at least 5cm or more from the intervening unit.

A firing unit on a higher elevation can fire at a target unit that is behind an intervening linear terrain feature, such as a low wall, fence, gate, etc, if the target is at least 5cm or more from the intervening linear terrain feature. (p. 54)

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Conclusions and observations

I started with the claim that hills are horrible in wargames rules. That is perhaps unfair.

I’m writing a set of rules for the South American Wars of Liberation, although these could probably be used for the Peninsular War and Carlist Wars. These wars are vaguely Napoleonics in nature. I was seeking inspiration for these rules from a sample of the wargaming rules I own. I wasn’t particularly inspired.

Hill profiles: Most rules just treat hills as blobs which won’t help on tables dominated by giant hill features. Those that are more nuanced mostly go for a predefined crest line – a ridge in my language – and my domes are neglected, as are the rounded slopes at the end of my ridges.

Line of sight: Mostly whole hill features block line of sight (blobs again), or the predefined crest line (hi, DBA 2.2). The most clever crest line rules came from Blitzkrieg Command IV and Volley & Bayonet; both use an implicit crest line based on the observers facing and the peak of the hill. I think, to get what I want from hills I have to combine the explicit (predefined) and implicit crest lines.

Uphill: Being uphill is often of combat benefit, usually for melee. Unfortunately most rules neglect to define “uphill”. DBA 2.2, Tilly’s Very Bad Day and Impetus were the best but could go further. The rules need to address edge cases e.g. fighting across the slope and being partially on the flat.

Overhead fire: Sadly neglected. Some rules cater for this but if I want to do something in this space, I’ll think I will start from a blank sheet.

Although this analysis of hills in wargaming rules was disappointing, the activity was useful as it, and the questions I posed, will help me frame a better set.

I’ll end with a major caveat to this post. A set of wargaming rules might still be a great game even if it fails to answer my questions on hills. Rules might simulate hills well given the level of simulation and the period. For example, if a set of rules does not give troops an advantage for being uphill / upslope then they will fail on some of the questions but still might be great. I think Crossfire is a great simulation despite having the most simplistic hills.

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Where to get Tilly’s Very Bad Day

Tilly’s Very Bad Day is available for Download (PDF).

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References

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Barker, P. C. (1971). Wargames Rules 1685-1845. Wargames Research Group

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Berry, P., Heading, D., and Sturges, E. (2010). Polemos English Civil War [2nd ed.]. Baccus 6mm.

Conliffe, A., Leach, C., Waxtel, D. (2008). Shako: Rules for Napoleonic Wargaming [2nd ed.]. Quantum Printing.

Fry, M. (2019). Blitzkrieg Commander, [4th ed.]. Pendraken Miniatures.

Harrison, C. (1995). The Age of Gunpowder. Chipco Games.

Hughes, T.,Humble, R., and Sprague E. (n.d.). 2 x 2 Napoleonics. Author. [Available on-line http://www.rodvik.com/2by2/]

Lockwood, R. (2009). Snappy Nappy: Simple, Subtle & Ultrafast Miniature Rules for the Napoleonic Era. On Military Matters.

Mustafa, S. A. (2015). Blücher. Author.

Mustafa, S. A. (2021). Lasalle: A Game of Tabletop Battles in the Age of Napoleon [2nd ed.]. Author.

Oliver, M. and Costa, M. (2014). Division Commander: Tactical Wargames Rules for the Napoleonic Era 1792-1840 Including the War of 1812 & 1st Carlist War [2nd ed.]. Capitan Games.

Priestley, R. and Hodgson, J. (2005). Warmaster Ancients. Warhammer Historical Wargames Ltd.

Saquero, A. (2011). Napoleon at War: Wargame Rules for Napoleonic Battles. Man at War

Sartori, L. (2008). Impetus. Dadi & Piombo.

Thomas, N. (2014). One-Hour Wargames: Practical tabletop battles for those with limited time and space. Pen & Sword Military.