- Fact 1: Fire Wall uses the
**firewallmaker**missile to spawn the fire patches. - Fact 1A: When you cast Fire Wall, two firewallmaker missiles are spawned. These travel in opposite directions, leaving two trails of fire in their path.
- Lemma 1B: The length of a Fire Wall is the combined distance traveled by two firewallmaker missiles.
- Lemma 1C: For each skill level, Fire Wall length increases by 2×(firewallmaker move distance increase)

- Proposition 2: In Missiles.txt, the
**Vel**and**MaxVel**columns determine the speed of a missile. These values are measured in pixels per frame. Let's call this px/frame for short.- Source 1: Missiles range/speed (Amazon Basin)
- Source 2: Missiles.txt Guide (Phrozen Keep)
- Source 3: [Tutorial] Calculating Missile Distance (Phrozen Keep)

- Fact 2A: In Missiles.txt, firewallmaker has Vel=12 and MaxVel=12.
- Lemma 2B: From Prop 2 and Fact 2A, firewallmaker travels at 12 px/frame.

- Proposition 3: In Missiles txt, Range and LevRange determine the duration of the missile. Range is the base duration at skill level 1, and LevRange is the additional duration per each skill level. These values are measured in frames (25 frame = 1 second).
- Source 1: Missiles.txt Guide (Phrozen Keep)
- Source 2: Diablo II Basin Wiki (Amazon Basin)

- Fact 3A: In Missiles.txt, firewallmaker has LevRange=2.
- Lemma 3B: From Prop 3 and Fact 3A, firewallmaker gains 2 frames of duration per each skill level. Let's call this frame/slvl for short.
- Lemma 3C: From Lemma 2B and Lemma 3B, firewallmaker travels an additional 12 px/frame × 2 frame/slvl = 24 px/slvl.
- Lemma 3D: From Lemma 1C and Lemma 3C, the length of Fire Wall increases by 24 px/slvl × 2 = 48 px/slvl, or 48 pixels per each skill level.

- Proposition 4: A yard is 48 pixels horizontally. ⇒
**Edit: This part is wrong, according to onderduiker @ Amazon Basin**

**Fire Wall gains 48px × (1 yard / 48px) = 1 yard per skill level.**

- Observation: Fire Wall length increases by 1 + 1/3 ≒ 1.33 yards per skill level. This contradicts the Conclusion above.
- Source: Fire Wall (Amazon Basin Wiki), plus many other D2 fansites

So....which part of my logic is wrong?