Slitherine

Help me understand Combat Power calculation — my formula doesn't match the game

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**TL;DR:** I tried to reverse-engineer `Unit_CombatPower` for Byzantine Light Archers (got ~9) and Skoutatoi (got ~32). But the game shows different numbers. Can anyone point out my mistakes or give me the actual in-game values so I can work backwards?

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Hi everyone,

I've been trying to reverse-engineer the `Unit_CombatPower` function from `Unit.BSF` to understand how Combat Power is calculated. But my results don't match what the game shows. Can anyone help me figure out what I'm missing?

## The Formula (as I understand it)

From `Unit.BSF`:

```c
FUNCTION Unit_CombatPower(unitID)
{
attack = Unit_Attack(unitID) + (Unit_FlankingMod(unitID) / 2) + (Unit_AttackAssaultChange(unitID) / 2);
defense = Unit_Defense(unitID) + (Unit_DefenseAssaultChange(unitID) / 2);
range = Unit_RangedAttackValue(unitID) + Unit_RangedMaxEffecDamages(unitID);
xp = Unit_GetXPLevel(unitID);

base = (Unit_GetHits(unitID) * UNIT_CP_HIT_INCh) + (Unit_GetEffec(unitID) * UNIT_CP_EFF_INCh);
base += (attack * UNIT_CP_ATK_INCh) + (defense * UNIT_CP_DEF_INCh);
base += (range * UNIT_CP_RNG_INCh) + (xp * UNIT_CP_EXP_INCh);

mult = (Unit_GetHits(unitID) * UNIT_CP_HIT_PERC) + (Unit_GetEffec(unitID) * UNIT_CP_EFF_PERC);
mult += (attack * UNIT_CP_ATK_PERC) + (defense * UNIT_CP_DEF_PERC);
mult += (range * UNIT_CP_RNG_PERC) + (xp * UNIT_CP_EXP_PERC);

result = base * (100 + mult);
result = DivideAndRound(result, 10000);

result = Pow(result, UNIT_CP_NUMERATORh, UNIT_CP_DENOMINATORh) / 10; // ^1.66
result = Max(1, result);

if (Unit_TemplateKind(unitID) == KIND_NAV)
result /= 2;

return result;
}
```

With the constants (from the comments):

```
UNIT_CP_HIT_INCh = 100
UNIT_CP_EFF_INCh = 50
UNIT_CP_EXP_INCh = 35
UNIT_CP_ATK_INCh = 25
UNIT_CP_DEF_INCh = 25
UNIT_CP_RNG_INCh = 10

UNIT_CP_HIT_PERC = 8
UNIT_CP_EFF_PERC = 22
UNIT_CP_EXP_PERC = 18
UNIT_CP_ATK_PERC = 15
UNIT_CP_DEF_PERC = 15
UNIT_CP_RNG_PERC = 6
```

## Example 1: Byzantine Light Archers

| Stat | Value |
|---|---|
| Hits | 1 |
| Effectiveness | 3 |
| Attack | 3 |
| Defense | 3 |
| RangedAttack | 7 |
| RangedMaxDamages | 1 |
| FlankingModifier | 1 |
| AtkAssaultChg | 0 |
| DefAssaultChg | 1 |
| XP Level | 0 |

### My calculation

**Step 1 — Compute derived stats:**

```
attack = 3 + (1 / 2) + (0 / 2) = 3 + 0 + 0 = 3
defense = 3 + (1 / 2) = 3 + 0 = 3
range = 7 + 1 = 8
xp = 0
```

> Note: integer division, `1/2 = 0`.

**Step 2 — Base value:**

```
base = (1 × 100) + (3 × 50) = 100 + 150 = 250
base += (3 × 25) + (3 × 25) = 75 + 75 = 150
base += (8 × 10) + (0 × 35) = 80 + 0 = 80
base = 250 + 150 + 80 = 480
```

**Step 3 — Multiplier:**

```
mult = (1 × 8 ) + (3 × 22) = 8 + 66 = 74
mult += (3 × 15) + (3 × 15) = 45 + 45 = 90
mult += (8 × 6) + (0 × 18) = 48 + 0 = 48
mult = 74 + 90 + 48 = 212
```

**Step 4 — Combine:**

```
result = 480 × (100 + 212) = 480 × 312 = 149,760
result = 149,760 / 10,000 = 14.976
```

**Step 5 — Pow(1.66):**

```
14.976 ^ 1.66 ≈ ?
ln(14.976) ≈ 2.7063
1.66 × 2.7063 ≈ 4.4925
e^4.4925 ≈ 89.4
result = 89.4 / 10 = 8.94
```

**Step 6 — Final:**

```
result = max(1, 8.94) = 8.94 ≈ 9
```

**My result: ~9**

But the game shows 5. Can anyone tell me where the discrepancy comes from?

## Example 2: Skoutatoi

| Stat | Value |
|---|---|
| Hits | 3 |
| Effectiveness | 3 |
| Attack | 6 |
| Defense | 8 |
| RangedAttack | 0 |
| RangedMaxDamages | 0 |
| FlankingModifier | 1 |
| AtkAssaultChg | 1 |
| DefAssaultChg | 0 |
| XP Level | 0|

### My calculation

**Step 1 — Derived stats:**

```
attack = 6 + (1 / 2) + (1 / 2) = 6 + 0 + 0 = 6
defense = 8 + (0 / 2) = 8 + 0 = 8
range = 0 + 0 = 0
xp = 0
```

**Step 2 — Base value:**

```
base = (3 × 100) + (3 × 50) = 300 + 150 = 450
base += (6 × 25) + (8 × 25) = 150 + 200 = 350
base += (0 × 10) + (0 × 35) = 0 + 0 = 0
base = 450 + 350 + 0 = 800
```

**Step 3 — Multiplier:**

```
mult = (3 × 8 ) + (3 × 22) = 24 + 66 = 90
mult += (6 × 15) + (8 × 15) = 90 + 120 = 210
mult += (0 × 6) + (0 × 18) = 0 + 0 = 0
mult = 90 + 210 + 0 = 300
```

**Step 4 — Combine:**

```
result = 800 × (100 + 300) = 800 × 400 = 320,000
result = 320,000 / 10,000 = 32.0
```

**Step 5 — Pow(1.66):**

```
32 ^ 1.66 ≈ ?
ln(32) ≈ 3.4657
1.66 × 3.4657 ≈ 5.7531
e^5.7531 ≈ 315.4
result = 315.4 / 10 = 31.54
```

**Step 6 — Final:**

```
result = max(1, 31.54) = 31.54 ≈ 32
```

**My result: ~32**

But the game shows 12.

## My Questions

1. **Are my constants correct?** I got them from comments in `Unit.BSF`.

2. **Integer division truncation:** In `attack = Unit_Attack + (Flanking / 2) + (AtkAssaultChg / 2)`, does `1 / 2` become 0 (integer) or 0.5 (float)?

Thanks for any help!

Won't the result of step 4 be 15 as its divide and round?
There should be a file where the real numbers are.

Thanks for replying.

Yes, the result of step 4 should be 15. However, the number still doesn't match which is confusing.

duirixuanyan wrote: Mon Oct 12, 2026 7:25 am Thanks for replying.

Yes, the result of step 4 should be 15. However, the number still doesn't match which is confusing.

Comments gets outdated so you need to find the file where the values are actually set.