Ti4 Battle Calculator






TI4 Battle Calculator – Twilight Imperium Combat Probability Tool


TI4 Battle Calculator

Strategic Combat Odds & Expected Hit Simulation for Twilight Imperium 4th Edition

Attacking Force


Number of War Suns in the fleet


Number of Dreadnoughts (Standard 5+)


Number of Cruisers (Standard 7+)


Number of Destroyers (Standard 9+)


Combined number of Carriers and Fighters


e.g., +1 for Morale Boost or Faction Ability

Defending Force


Number of War Suns defending


Number of Dreadnoughts (Standard 5+)


Number of Cruisers (Standard 7+)


Number of Destroyers (Standard 9+)


Combined number of Carriers and Fighters


Defensive bonuses (e.g., Bunker, Tech)


Attacker Expected Hits
1.90

Expected hits per round based on unit combat values and counts.

Defender Expected Hits
0.80

Attacker Health (EHP)
9

Defender Health (EHP)
5

Combat Power Distribution

Comparison of Attacker vs Defender offensive capacity (Expected Hits per round).

Unit Type Standard Hit Value Attacker Dice Defender Dice Unit Role
War Sun 3 (x3) 0 0 Heavy bombardment & fleet core
Dreadnought 5 2 1 Frontline damage & sustain
Cruiser 7 1 0 Rapid response unit
Destroyer 9 0 2 Screening & Anti-Fighter Barrage
Fighter/Carrier 9 4 2 Hit absorption (fodder)

What is a TI4 Battle Calculator?

A ti4 battle calculator is an essential strategic tool for players of Twilight Imperium 4th Edition. In a game where a single lost fleet can shift the balance of the galaxy, understanding the mathematical probability of combat outcomes is vital. This calculator evaluates the aggregate “Expected Hits” of a fleet, accounting for different unit combat values and quantities. Whether you are planning a daring strike on Mecatol Rex or defending your home system, using a ti4 battle calculator helps remove the guesswork from your tactical decisions.

Many players rely on intuition, but the dice in TI4 are notoriously fickle. A ti4 battle calculator converts unit stats into a single metric of offensive power. It’s not just about who has the most ships; it’s about the probability of those ships landing hits against the enemy’s health pool (Sustain Damage and total units).

TI4 Battle Calculator Formula and Mathematical Explanation

The math behind a ti4 battle calculator is based on the Expected Value (EV) of a discrete probability distribution. Since each die roll is independent, we sum the probabilities of each unit’s success.

Formula: Expected Hits = Σ (Number of Units × Number of Rolls per Unit × (Success Probability))

In TI4, a success occurs if a D10 roll is greater than or equal to the unit’s Combat Value. Thus, Success Probability = (11 – (Combat Value – Modifiers)) / 10.

Variable Meaning Unit Typical Range
Combat Value The number required to score a hit D10 Target 3 to 9
Modifier Bonuses from tech (Plasma Scoring) or action cards Flat integer -1 to +2
Expected Hits The average number of hits per combat round Hits 0 to 15+
EHP Effective Health Points (Units + Sustain Damage) Hits absorbed 1 to 20+

Practical Examples (Real-World Use Cases)

Example 1: The Standard Skirmish
An Attacker brings 2 Dreadnoughts and 2 Fighters against a Defender with 1 Carrier and 4 Fighters.
Using the ti4 battle calculator, the Attacker’s Expected Hits = (2 * 0.6) + (2 * 0.2) = 1.6 hits.
The Defender’s Expected Hits = (1 * 0.2) + (4 * 0.2) = 1.0 hits.
Interpretation: The attacker has a significant offensive advantage and will likely win over multiple rounds due to higher hit probability and Sustain Damage on Dreadnoughts.

Example 2: The War Sun Threat
A War Sun (3 rolls at 3+) is attacking a fleet of 8 Fighters.
War Sun Expected Hits: 3 * 0.8 = 2.4 hits.
Interpretation: While the War Sun is powerful, it will take at least 4 rounds of combat on average to clear the fighter screen, during which the fighters (8 * 0.2 = 1.6 hits/round) might destroy the War Sun if it lacks its own screen.

How to Use This TI4 Battle Calculator

1. **Enter Attacker Units:** Input the quantity of each ship type currently in the active system. Adjust the Combat Modifier if you have technology like Antimass Deflectors or have played a Morale Boost card.
2. **Enter Defender Units:** Do the same for the defending force. Don’t forget to include units that might participate via Space Cannon or faction abilities.
3. **Analyze Expected Hits:** Look at the primary result. This represents how many hits you are likely to inflict in the *first* round of combat.
4. **Check EHP:** Compare the health pools. If your expected hits exceed their health, you have a high chance of a “wipe” in that round.

Key Factors That Affect TI4 Battle Calculator Results

1. **Unit Combat Values:** The core of the ti4 battle calculator. Lower numbers (like the War Sun’s 3+) are vastly superior to higher numbers (Fighter’s 9+).
2. **Action Cards:** Cards like “Morale Boost” (+1 to rolls) significantly shift the odds, especially for fleets with many units.
3. **Faction Abilities:** The Jol-Nar’s -1 penalty or the L1Z1X’s +1 with flagship drastically change the math within the ti4 battle calculator.
4. **Technology:** Upgrading to Cruiser II or Destroyer II changes their combat values, increasing your expected hit output.
5. **Sustain Damage:** Units like Dreadnoughts and War Suns effectively have 2 health points, doubling their contribution to the fleet’s survivability.
6. **Fighter Screens:** Using cheap units to absorb hits allows your high-value damage dealers to stay in the fight longer, a concept the ti4 battle calculator highlights through the EHP metric.

Frequently Asked Questions (FAQ)

Does the calculator include Anti-Fighter Barrage?

This simplified version focuses on general combat rounds. For AFB, calculate the expected hits separately using the Destroyer counts and the 9+ (or upgraded) value.

How does Sustain Damage work in the calculator?

In the EHP (Effective Health) calculation, units with Sustain Damage are counted as 2 health points instead of 1.

Can I use this for Ground Combat?

Yes, simply enter your Infantry or Mechs into the appropriate slots (usually the Fighter/Carrier slot if they hit on 8+ or 9+) and adjust modifiers.

Is a 1.0 expected hit a guarantee?

No. An EV of 1.0 means on average you get one hit, but in TI4, “Average” is just the center of a wide bell curve. You could get 0 or 4.

How do modifiers affect the calculation?

A +1 modifier reduces the required roll (e.g., a 7+ becomes a 6+), effectively increasing the probability of a hit by 10% per die.

Why use a TI4 battle calculator instead of counting ships?

Counting ships ignores the quality of those ships. 5 Fighters have the same health as 5 Dreadnoughts but significantly lower damage output.

Does the calculator handle the flagship?

Since flagships vary by faction, you should input them as the unit type they most closely resemble (usually a War Sun or Dreadnought) and adjust the modifier.

What is the most important stat in the calculator?

Expected Hits per Round is the best indicator of fleet strength, as it accounts for both ship quality and quantity.

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