FEATURE FOCUS #1: Elevation
Today we’re kicking off a series of blogs that are a little different to our norm in which we take a deep dive into some of the grittier aspects of Total War: WARHAMMER III, tearing into the real meat of the game and pulling apart its entrails for all to see.
The aim is to explore some of the often-overlooked areas of the game at a developer level, with the aim of squashing some of the mysteries surrounding the many, many systems found in WARHAMMER III.
Helping us get our head round things is WARHAMMER III designer William Håkestad.
We begin with a look at elevation. How much does having the high ground really change the course of battle? Let’s find out!
You’ve quite likely seen the “Units with the high ground enjoy a significant advantage when fighting on sloped terrain” loading screen tip, but have you ever wondered ‘how’?
Let’s peel back the curtain a bit using a force that some say is more dangerous than any of the dark gods… Maths!
In Total War, you control ‘units’ that comprise individual ‘entities’. For example, an Empire Swordsmen unit is a collection of 120 Swordsmen entities.
The elevation calculations happen at the entity level. This means that when calculating the bonus an attack should gain from elevation, the relative height between the attacking and defending entities is determined regardless of the overall situation of their units. Therefore, the numbers can vary when fighting on particularly bumpy terrain, or if a unit is deployed across a slope.
Regarding about elevation in combat, there are three key cases where it becomes relevant:
- Melee Attacks
When a projectile hits an entity, we generate a ‘height delta’ that is equal to the difference in vertical height between the firing and receiving entities, calculated from the base of each (sorry Henri – being tall does not actually factor into elevation modifiers).
We use this delta to give the unit a height coefficient value for the attack. This coefficient linearly scales up to a maximum delta of 40 metres, at which point it caps out at 30%. So, a ranged unit firing down upon their target from 40 metres or above is doing a respectable 30% extra damage!
It’s important to highlight that this delta can also be a negative, and a ranged unit firing at a target that is 40m above them is doing 30% less damage. So, in practice, assuming a pair of otherwise equally matched ranged combatants are shooting at each other, the one with the high ground is enjoying 184% of the damage of their target’s volley!
This isn’t mutually assured destruction – it’s a complete slaughter.
As a practical example, an Empire Crossbowman firing at an Empire Swordsman roughly 32 meters below them gains one point of armour piercing and four points of base missile damage from his elevation, netting him a modest four extra damage after calculating for the armour roll in this interaction.
Now four damage might sound like a very small difference, but consider that an Empire Swordsman has 69 hit points for every entity in the unit.
- 69/23 = 3
- 69/19 = 3.6
By taking this high ground, the Crossbowman can potentially take out a Swordsman in three crossbow bolts instead of four. Plus, this interaction repeats over 100 times in every volley, meaning that small, consistent bonuses can cascade into huge performance improvements in practice.
Let’s look at one final example:
In this case, the high ground advantage has an approximate coefficient of 25%, and this bonus compounds into the unit with an elevated position, letting them rout the otherwise identical enemy unit while maintaining an additional 1,000 health, and with twenty extra entities left standing. It will be in much better shape later in the battle if it has a chance to contribute again.
Taking all of this into account, here are two common scenarios that you can take advantage of in WARHAMMER III:
- Walls and other elements common to settlement battles provide opportunities to gain an elevation bonus over your opponent, alongside some potential added benefits like partial cover against projectiles.
- Flying units hover roughly 16 meters above the ground, and so they benefit from an elevation damage bonus of 12% if their target is standing on ground level. Remember that this also means they take roughly 12% less damage from missiles fired from those same targets. As such, flying units placed above already tall terrain compound their additional height and quickly reach high coefficients (though, like all units, a height delta exceeding 40 metres does not grant any further benefit).
This works exactly like the projectile examples above in every way with a single, functional difference – the maximum coefficient is achieved at one meter of difference between the attacker and the defender.
It’s worth remembering that these deltas are calculated between individual entities in their respective units, thus introducing a much greater level of uncertainty into an engagement as fighters jostle around in the fray, gaining and losing height advantage relative to their target. Over an entire engagement, however, the unit with the overall better position on a slope will average higher, reliable coefficients, alongside the much stricter requirements for the height delta of one meter.
Let’s pit a unit of Swordsmen against a unit of Spearmen on a very steep slope.
Normally, Swordsmen can handle the more specialised Spearmen with ease, thanks to their greater melee stats and higher damage. But, when the Spearmen attack from the high ground, their advantage swings this matchup back in their favour, further highlighting how the effective usage of the terrain can let a unit take fights it would otherwise be unable to.
In the engagement pictured above, the usual decisive victory for the swordsmen gets flipped to a narrow victory for the spearmen!
The high ground isn’t just about fighting. OK, it’s mostly about fighting, but slopes can also affect how quickly a unit travels and how much fatigue they suffer while doing it.
Take this Red Crested Skink Chief running up and down the slopes of the Grimminhagen.
Units moving across uneven surfaces have a value called a ‘locomotion gradient’ which has a value of zero on a perfectly flat surface and trends either upwards or downwards when moving up or down a slope.
Travelling downhill here, the Red Crested Skink Chief reports an ‘actual speed’ value of 5.8 m/s, which is higher than the 46 listed on his unit info panel (we multiply all speed numbers by 10 for display in game to help keep the whole numbers nice and readable!)
This speed change is because the slope he’s moving down has a locomotion gradient of roughly -0.26, which we subtract from the default speed multiplier of 1.0, resulting in a 26% speed increase. Technically, a unit can achieve up to a 50% speed increase given a comically steep surface, but we cap the value there for sanity purposes.
Spinning him around and running him back up the slope slows him down to a more modest 3.62 actual speed value – a 22% decrease, roughly.
In short, if you’re trying to put some space between yourself and some enemy archers, you should probably not run up a hill! And, equally, you should probably not deploy your own vulnerable ranged units near the base of a hill, where the enemy can take advantage of the increased speed to close the gap faster while simultaneously taking less damage from your low ground fire.
Collision impact damage must also be considered. This is a very complex topic that we might dive into more deeply in a later blog, but the short and sweet version reads like this: Entities moving faster when they collide with the enemy will deal more damage and cause higher knockback based on their relative velocity to the target.
In other words, the most brutal charges are delivered downhill!
Finally, the locomotion gradient is also used to penalise the fatigue of units moving up steep slopes, though do keep in mind that no fatigue benefit is gained by going downhill.
In our example above, the gradient of 0.26 triggers the most severe fatigue penalty, increasing the amount of fatigue the unit gains by a whopping 150%!
Here are the fatigue numbers in detail:
- Gradients steeper than 0.2 increase fatigue gain by 150%
- Gradients steeper than 0.1 increase fatigue gain by 100%
- Gradients steeper than 0.05 increase fatigue gain by 50%
BREAKING THE RULES WITH STRIDER
Got all that? Good, because units with the ‘Strider’ attribute ignore a lot of what’s listed above!
A Strider unit doesn’t suffer any of the typical penalties when it comes to dealing damage, although it is still subject to the typical penalties when it comes to receiving it. So, such a unit deals full damage (but no extra) while shooting at someone above it and deals full damage (plus extra) when shooting someone below it.
A Strider’s actions negate the penalties, but his reactions do not.
And we’re done! The ground has levelled out and everyone’s knackered. Hopefully you learned something new and it didn’t leave you tilted.
Our next Feature Focus blog will examine at the overall concept of damage – both how it’s dealt and how to defend yourself against it. Also on the way are deep dives into projectiles and target penetration. Plus, we’ll be parallel parking our way into the topic of chariots, mass and charges.
As always, your feedback is welcomed. See you on the battlefield!
– The Total War Team