Here is the armor formula for London 2038.

**1. Armor formula**

Definitions:

A = armor, as shown on the character screen.

DA = Damage absorption, as shown on the character screen.

K(L) = A formula based on character level. The formula is K(L) = 20*L + 80.

If you look at your character screen, you will see that

DA = A / (A + K(L)).

Try it. You’ll see that the formula shows you what you see in game.

Someone posted this formula to the original game’s forum, forums.hellgatelondon.com. In the original game, K(L) was 5*L + 20, and likewise, armor values were 1/4 of what they are now.

When A = K(L), DA = 50%. K(L) is the amount of armor you need to give you 50% damage absorption. At level 50 this is 1080.

Solving for A in the armor formula tells you how much armor you need to get a certain DA:

A = K(L) * (DA / (1 - DA)).

**2. Effective health**

Definitions:

H = health (total health, including all health bonuses).

E = effective health; the amount of incoming damage you can take before dying.

The meaning of the term “damage absorption” is that

E = H / (1 - DA).

For example, if DA = 75%, E = H / (1 - 0.75) = H / 0.25 = 4 * H. Your 75% damage absorption reduces all damage to 1/4 of its original value, so you can take 4 times as much damage before dying.

**3. Armor required for effective health**

If you plug in the armor formula to the effective health formula and simplify the expression, you’ll see that

E = H (1 + (A / K(L))).

The effect of armor on your effective health is linear. Every time you add K(L) more armor, you increase your effective health by 100% of H, your health. When A = K(L), that’s easy to see, because your DA = 50%. You absorb half of incoming damage, doubling your effective health.

Here are some values of A, DA, and E.

The character screen rounds DA down to the nearest percent.

```
Effective
Armor DA Health
---------- --- ---------
1/4 * K(L) 20% 125% * H
1/2 * K(L) 33% 150% * H
3/4 * K(L) 42% 175% * H
1 * K(L) 50% 200% * H
2 * K(L) 66% 300% * H
3 * K(L) 75% 400% * H
4 * K(L) 80% 500% * H
5 * K(L) 83% 600% * H
6 * K(L) 85% 700% * H
7 * K(L) 87% 800% * H
8 * K(L) 88% 900% * H
9 * K(L) 90% 1000% * H
```

**4. Level scaling**

This is kind of a technical footnote.

The main thing to understand in this section is that damage is affected by hidden factors, one of which is the level of the attacker.

When the person posted the armor formula, they said the character level L is actually the attacker’s level, rather than the defender’s level. That means the higher the attacker’s level, the more armor you need to get the same damage absorption. What the character sheet shows is the value of DA for an attacker of your own level.

I don’t know how that person got that information, nor whether it’s true, but I do know another piece of evidence that the game uses the attacker’s level to scale damage. Another thing posted to the original forum was a spreadsheet named monsters.xls containing game data that someone said they got via reverse engineering. One tab in monsters.xls was “Scaling for level diff”, a table of scaling values based on the relative levels of the attacker and defender, and on whether the attacker was a player or a monster. For example, for a player attacking a monster 11 or more levels higher than the player, the table showed a scaling factor of 1%, a huge reduction in damage.

My guess is that *both* of those level-based scaling factors were in effect in the original game. They’re probably in 2038 too.

So you might imagine that, say, Shulgoth has 100 Health and 80% damage absorption, and it’s easier for higher level characters to kill him because their weapons and skills do more damage. But the game actually applies a lot of complicated scaling to the numbers it shows you.