War Machine: Field Manual

How to use the Definitive Edition calculator for BECMI mass combat.

Quick Start: This tool automates the math from the Rules Cyclopedia War Machine system. It calculates the Battle Rating (BR) for two opposing forces, applies tactical modifiers, rolls the dice, and determines casualties based on the authentic Combat Results Table (CRT).

1. Building Your Forces (BFR)

The core of War Machine is the Basic Force Rating (BFR). You do not need to calculate this manually. Simply enter the stats into the Force A and Force B panels.

The Four Factors

The system calculates BFR based on these four components:

Leadership: The level and mental stats of the commander. High-level leaders significantly boost BFR.
Experience: The average level of officers and troops, plus their history of victories (+1 BFR) or routs (-1 BFR).
Training: Weeks spent training together. The base score starts at 5 and increases with every week of training.
Equipment: Weapon quality (Good/Excellent), AC (AC 5 or better), and racial bonuses (Elves/Dwarves get +15).

Troop Class Bonuses

Once the BFR is set, the system adds bonuses based on the composition of the army. The value of these bonuses depends on the army's quality (BFR / 10).

Mounted: Check if >20% of the force is cavalry.
Missile: Check if >20% of the force has bows/crossbows.
Magic: Check if >1% of the force can cast spells.
Flying/Special: For armies with flyers, regenerators, or special abilities.

2. The Tactics Matrix

Before rolling, you must select a Tactic for each side. This is the "Rock-Paper-Scissors" element of the system. Choosing the right tactic against your opponent grants a massive +20 BR Bonus.

Your Tactic	Strong Against (+20)	Weak Against (-20)
Attack	Trap	Envelop
Envelop	Attack, Hold	Trap
Trap	Envelop	Attack, Hold
Hold	Trap	Envelop
Withdraw	(Safe retreat)	(None)

3. Modifiers & Situational Rules

The center panel handles battlefield conditions. These toggle buttons apply instant math modifiers.

Troop Ratio: The system automatically compares the size of the two armies. If one army is significantly larger (e.g., 2:1 or 4:1), they receive a BR bonus (up to +50).
Fortified: Checking Defender Fortified multiplies the defender's effective size by 4 for ratio calculations and adds +10 BR.
Terrain: Gives +20 BR. Use this for high ground, defending a bridge, or fighting in favorable woods (Elves).
Traitor: A specific +20 BR bonus for the attacker if they have a spy inside the walls.

4. Reading the Results

When you click Roll Battle, the system rolls d100 for both sides and adds it to their total BR. The difference determines the outcome.

The Combat Log

The log will display:

The Victor: Based on the Total Score (BR + d100).
Casualties: The number of troops lost based on the CRT percentages.
Location Change: Whether the loser holds the field, retreats, or routs.

Apply Casualties Button: Every log entry has a green button. Clicking this will automatically subtract the dead troops from the input fields for both armies, allowing you to immediately start the next turn or siege week.

5. Saving Your Data

The simulator uses your browser's Local Storage. This means you can close the tab or refresh the page, and your "Orc Horde" stats, current troop counts, and tactical choices will be exactly where you left them.

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