Combat Calculator — Known Limitations
The combat calculator solves Eclipse 2E battles using exact dynamic programming with a Monte Carlo fallback for cases the exact solver can't reach within its compute budget. Most fights resolve in under a second. This page lists the cases where the calculator is known to be approximate, slow, or missing.
Result modes
Every result is badged in the top-right of the result panel:
- Exact — the engine ran to a closed-form probability. The attacker-win and per-ship survival numbers are correct to the precision shown.
- Approximate (Monte Carlo) — the exact solver hit its compute budget and the engine fell back to a Monte Carlo simulation (30 000 trials, greedy targeting heuristic). Typical accuracy: ±1 pp on simple fights, up to ±5 pp on certain complex multi-class engagements. Read the displayed percentage with that uncertainty in mind.
Where the engine is approximate
MC fallback triggers
MC fallback engages when the exact DP would exceed the operations budget (currently 50 M ops, ~3-5 s of compute). In practice this happens on:
- Asymmetric fleets with 3 or more distinct ship types per side (e.g. 1 Dread + 2 Cru + 3 Int vs 1 SB + 2 Dread). Most real games involve 1-2 distinct types per side, so this is rare in normal play.
- Multi-cannon-type Cruiser/Dread builds (e.g. 2 plasma + 3 antimatter on a single ship) when the defender has many low-HP targets to allocate damage across.
Outright unsupported
The calculator currently does not model:
- Multi-side battles (3-way / 4-way / N-way in a single hex). The engine assumes binary attacker / defender. Eclipse 2E supports more than two players sharing a hex; those resolve sequentially in initiative order under the rulebook, which is a different combat model.
Engine performance notes
- Page may freeze briefly on the largest cases the exact DP attempts. The solver runs synchronously on the main thread. A Web Worker offload is on the roadmap.
- Default OPS budget: 50 M operations. If the result returns instantly with the "Approximate" badge, the exact path was skipped to preserve responsiveness.
Reporting issues
If the calc gives a result that contradicts another exact reference, please send the following:
- The two fleet configurations (attacker and defender, all parts).
- The result the calc shows (with the Exact / Approximate badge).
- The result the other reference shows for the same fleet.
- Whether AM Splitter is active on either side.