Explosion falloff & demolition
Explosion distance uses two confirmed primary falloff curves. Demolition force follows the primary blast scale, and armor penetration drops by one as soon as falloff begins.
- Inner radius
- Full damage and Demo
- Outer radius
- 0 primary damage and Demo
- Falloff AP
- AP0 − 1
Explosion falloff calculator
Start from a resolved explosive preset or switch to Custom and enter your own authored values. The calculator separates primary scale, damage, Demolition Force, AP, and push into their own graphs so step changes and different falloff rules remain visible instead of being flattened into one curve.
Hover a graph to inspect exact values. Move near a threshold to snap to it. Click to pin the inspector.
Primary scale
How much of the authored primary effect remains.
Damage
Raw primary blast damage before target-specific modifiers.
Demolition Force
Full through the inner radius, then scaled to zero at the outer radius.
Armor penetration
AP changes as a step at the inner-radius boundary.
Mapped primary stagger
The mapped stagger field stays at authored strength while the primary packet remains active and penetration permits it.
Primary push
The mapped primary push uses a 75% minimum distance multiplier while the primary blast remains active.
Primary damage, demolition, and status strength use the selected curve. Shockwave/reaction behavior is separate.
Source comparison
These graphs put the Eagle 500 kg, EAT-411 Leveller, Orbital Precision Strike, and Hellbomb-family profile on the same distance axis. Damage and Demolition Force show the source-specific primary curve, AP shows the inner-radius step, and the push and stagger graphs show why visible reactions can remain strong after damage has already fallen sharply. Hover for exact values or click to pin a distance threshold.
The Orbital Precision Strike line represents its 1500-damage explosion only; its separate 4000 ballistic projectile impact is not part of an explosion falloff curve. The Eagle 500 kg and Incinerator FRV fuel explosion currently overlap in the mapped primary stats, so the comparison graphs use one line for that shared profile rather than drawing two indistinguishable curves.
Hover any graph for exact values and threshold snapping; click to pin the inspector. The Orbital Precision Strike line is its 1500-damage explosion only—the separate 4000 ballistic direct-hit projectile is not part of these falloff curves. The Incinerator FRV fuel explosion overlaps the Eagle 500 kg main profile in these mapped primary stats, so it is omitted as a duplicate line.
Raw primary blast damage
Before armor, resistance, and target-specific modifiers.
Demolition Force
Full through the inner radius, then scaled by the source's primary curve.
Armor penetration
Full AP inside the inner radius, then one point lower until the primary blast ends.
Mapped primary push
Primary packet push uses a 75% floor while the primary blast remains active.
Mapped primary stagger
The mapped stagger field remains at authored strength while the primary packet remains active and penetration permits it.
Distance rules
| Effect | Distance behavior | Notes |
|---|---|---|
| Damage | Falls with the primary explosion scale. | Standard and wide-blast profiles use different curves. |
| Demolition Force | Full inside the inner radius, scales through the outer band, reaches 0 at the outer radius. | Uses the same primary scale as blast damage. |
| Armor penetration | Full AP0 inside the inner radius; loses 1 AP once falloff begins. | The primary blast does not use projectile impact-angle lanes. |
| Stagger Force | The mapped primary stagger value is not continuously multiplied by distance scale. | It remains authored strength while the primary packet is active and penetration permits it. |
| Push Force | The mapped primary path uses a 75% minimum distance multiplier. | Shockwave/reaction behavior outside the primary blast is separate. |
| Status strength | Numeric status strength falls with the primary explosion scale. | Downstream duration or threshold behavior depends on the status system. |
Demolition Force
The mapped type-4 packet builder keeps the authored Demolition Force unchanged while the blast is at full strength. Once falloff begins, the same primary scale used by the blast is applied to Demolition Force. If the scale reaches zero at the outer radius, primary Demolition Force reaches zero with it.
This makes structure destruction distance-sensitive. A blast can still be inside its listed outer radius but no longer meet a structure's demolition threshold. Helldivers are advised to place demolition-critical explosions inside the inner radius whenever practical.
Falloff curves
Let x be progress through the falloff band: 0 at the inner radius and 1 at the
outer radius. Standard falloff uses 1 − √x, which loses strength
quickly after leaving the inner radius. Wide-blast falloff uses 1 − x², which keeps
most of its strength until much farther through the same band.
Live validation
A controlled G/40-K Melta Mine test against a TD-110 Maelstrom captured 40 primary explosion
evaluations across the full-strength, falloff, and zero-scale ranges. For every captured
regular-explosion evaluation, the runtime primary scale matched 1 − √x. The
maximum absolute difference across all 40 samples was less than 4.3 × 10⁻⁸.
The same live captures also showed the penetration step directly: the AP7 explosion became AP6 as soon as the target point moved beyond the 2.5 m inner radius. Candidates at or beyond the 6 m primary outer radius continued to reach primary evaluation with a scale of 0 and therefore 0 evaluated primary damage.
| Captured distance | Recorded primary scale | 1 − √x prediction |
|---|---|---|
| 2.582 m | 0.846800 | 0.846800 |
| 3.763 m | 0.399396 | 0.399396 |
| 4.595 m | 0.226349 | 0.226349 |
| 5.989 m | 0.001627 | 0.001627 |
Wide-blast falloff still needs the same live check.
This test directly validates the standard curve and AP step. The wide-blast 1 − x² curve remains code-confirmed but has not yet been captured point-by-point with the same runtime instrumentation.
500 kg vs Leveller
Both current profiles use a 10 m inner radius, 25 m outer radius, and 35 m shockwave radius. The 500 kg main blast uses wide-blast falloff; the EAT-411 Leveller uses standard falloff. Their radius labels therefore do not imply the same damage or demolition performance between 10 and 25 m.
| Distance | Eagle 500 kg | EAT-411 Leveller |
|---|---|---|
| 10 m | 100% · 1500 damage · 50 Demo | 100% · 2500 damage · 40 Demo |
| 12.5 m | 97.2% · 1458 damage · 48.6 Demo | 59.2% · 1479 damage · 23.7 Demo |
| 15 m | 88.9% · 1333 damage · 44.4 Demo | 42.3% · 1057 damage · 16.9 Demo |
| 17.5 m | 75.0% · 1125 damage · 37.5 Demo | 29.3% · 732 damage · 11.7 Demo |
| 20 m | 55.6% · 833 damage · 27.8 Demo | 18.4% · 459 damage · 7.3 Demo |
| 22.5 m | 30.6% · 458 damage · 15.3 Demo | 8.7% · 218 damage · 3.5 Demo |
| 25 m | 0% primary damage · 0 Demo | 0% primary damage · 0 Demo |
AP falloff
The primary blast uses its first AP value rather than the ordinary projectile impact-angle lanes. It keeps that AP while the blast is at full primary strength.
As soon as falloff begins, effective AP becomes max(AP0 − 1, 2).
An AP6 explosion is therefore AP6 inside the inner radius and AP5 through its primary falloff band. This change happens immediately after the full-strength boundary rather than gradually with distance. Live Melta Mine captures independently observed the same transition from AP7 inside the inner radius to AP6 throughout the falloff band.
Shockwaves
Both falloff paths also have separate directional and reaction handling. The primary damage, Demo, stagger, and push fields therefore do not describe every visible reaction outside the primary outer radius. Live instrumentation can now see candidates that continue through primary evaluation after the primary scale has reached 0, but that alone does not prove a shockwave hit or unobstructed line of sight. The separate reaction and occlusion path remains under investigation.
Evidence status
| Finding | Evidence status |
|---|---|
| Standard-falloff explosions use 1 − √x between inner and outer radius. | Code + live confirmed |
| Wide-blast explosions use 1 − x² between inner and outer radius. | Code confirmed · live not tested |
| Demolition Force is full inside the inner radius and multiplied by the primary scale during falloff. | Code confirmed |
| Primary explosion AP loses one point once falloff begins, with a minimum of AP2. | Code + live confirmed |
| The 500 kg main blast uses wide-blast falloff; the EAT-411 Leveller uses standard falloff despite matching 10 / 25 / 35 m radii. | Current data confirmed |
| Primary explosion candidates can reach evaluation with a zero damage result once the primary scale reaches 0. | Live confirmed |
| Some candidates can evaluate to positive damage without a later Health application; the downstream rejection reason is not yet mapped. | Observed · cause unresolved |
| Every reaction beyond the primary outer radius has been mapped to a named stagger or push mechanic. | Unresolved |
Research basis
Methodology How the OTL separated primary blast falloff from shockwave behavior
Current code verification establishes two primary falloff calculations. Controlled Melta Mine testing independently confirms the standard curve and AP step. Equivalent point-by-point live validation of the wide-blast curve is still pending.
Evidence standard
How the OTL separates code confirmation, controlled live testing, and behavior that remains unresolved.
How the OTL rates evidence
The OTL rates code evidence and live-game evidence separately. A mechanic can be clear in code but still need a controlled gameplay check for hidden state, ordering, or another runtime factor.
Live confirmation means controlled gameplay or instrumented runtime observation, not player impression alone.