Advanced Fleet Inputs
Adjust each unit count, combat target, and dice count. Positive modifiers improve rolls by lowering the required target number.
Example Data Table
This sample shows a balanced space fight with capital ships and fighter screens.
| Side | Fighters | Destroyers | Carriers | Cruisers | Dreadnoughts | Modifier | Reroll Rate |
|---|---|---|---|---|---|---|---|
| Attacker | 6 | 1 | 1 | 1 | 2 | 0 | 0% |
| Defender | 4 | 2 | 1 | 1 | 1 | 0 | 0% |
Formula Used
Base hit chance per die: p = (11 - combat target) / 10
Effective target: target = base target - combat modifier
Reroll adjusted chance: p2 = p + (1 - p) × reroll rate × p
Expected hits: unit count × dice per unit × p2
Effective hit points: unit count + available sustain damage
Simulation: Each trial rolls battle rounds, applies simultaneous hits, and removes casualties by screen order.
This calculator uses editable combat values because factions, technologies, unit upgrades, action cards, leaders, and table agreements can change outcomes. Use the fields to match your game state.
How to Use This Calculator
- Enter attacker and defender unit counts.
- Change combat targets when units are upgraded.
- Add combat modifiers for abilities or temporary bonuses.
- Use opening hits for effects before normal combat.
- Set reroll rate when a side can reroll missed dice.
- Enable sustain damage for capital ships and mechs.
- Choose simulation count and round cap.
- Press calculate, then export the report as CSV or PDF.
Battle Planning Article
Why Battle Math Matters
Twilight Imperium battles feel dramatic because every roll can change the map. Still, strong planning reduces painful surprises. A calculator helps you study risk before committing command tokens, ships, and political pressure. It gives a clear view of expected hits, survivability, and likely momentum.
Fleet Shape Changes Outcomes
A large fighter screen can protect expensive ships. Dreadnoughts and war suns bring strong damage output. Carriers may hold the fleet together, but they are not always powerful attackers. Destroyers can matter when fighter-heavy fleets appear. The best fleet is not always the largest fleet.
Modifiers Are Very Powerful
Small changes in combat value can shift odds quickly. A one-point bonus may improve every die in the fleet. Rerolls can also create strong value. They are most useful when many dice are rolled. Opening hits are different. They remove enemy staying power before normal combat starts.
Sustain Damage Adds Staying Power
Sustain damage can keep key ships alive for another round. That extra round may produce several more hits. However, direct hit risks can punish damaged capital ships. This tool lets you include that danger. You can test conservative and aggressive settings.
Use Results With Judgment
Simulations show likely outcomes, not certainties. The board state still matters. Retreat options, objectives, reinforcements, action cards, and diplomacy may change the correct decision. A low-probability attack can still be worth it. A favored attack can still fail. Use the numbers as a guide, then decide with strategy.
FAQs
1. Is this calculator official?
No. It is a fan-made planning tool. It uses editable values so you can match your own table, upgrades, and special effects.
2. Can I change unit combat values?
Yes. Every unit has editable target numbers and dice counts. Use those fields for upgrades, faction units, leaders, or house rules.
3. What does combat modifier mean?
A positive modifier improves rolls by lowering the needed target number. A negative modifier makes hits harder by raising the effective target.
4. What are opening hits?
Opening hits represent damage before normal combat rounds. Use them for bombardment, space cannon, anti-fighter effects, or similar pre-combat damage.
5. Why do results change after each calculation?
The calculator runs dice simulations. Random trials can vary slightly. Increase the simulation count for steadier percentages.
6. Does sustain damage affect win odds?
Yes. Sustain damage increases staying power. It can help important ships survive longer and roll more dice in later rounds.
7. Can I export the battle report?
Yes. Use the CSV button for spreadsheet data. Use the PDF button for a clean printable summary.
8. Should I trust the highest percentage every time?
No. Consider objectives, retreats, politics, reinforcements, and timing. A strong percentage is useful, but strategy decides the final move.