Calculator Form
Formula Used
Base unit CR: Use the individual creature CR. For cavalry, use the higher value between rider CR and mount CR.
Army Challenge Rating: ACR equals base unit CR moved along the CR scale by the selected army size step modifier.
Army hp: ACR × average hit die value. The calculator rounds down and keeps a minimum of 1 for valid armies.
Offense Modifier: ACR + commander bonus + tactic bonus + resource bonus + strategy adjustment + morale adjustment + other bonuses.
Defense Value: 10 + ACR + fortification bonus + settlement defense bonus + strategy adjustment + other bonuses.
Consumption: ACR ÷ 2 each week, with a minimum weekly value of 1 BP.
Damage Test: d20 roll + total OM − enemy DV. Negative damage is treated as zero.
How to Use This Calculator
- Enter the army name and the usual creature type.
- Select the creature CR for a typical member of the army.
- Choose cavalry if mounts are important to the formation.
- Select the army size category that best matches the force.
- Add commander, tactic, resource, strategy, morale, and defense bonuses.
- Enter enemy DV and enemy ACR for battle comparison.
- Press the calculate button to show results above the form.
- Use the CSV or PDF buttons to save the result.
Example Data Table
| Army | Unit CR | Size | Step | Estimated ACR | HD | Notes |
|---|---|---|---|---|---|---|
| Orc Warrior Company | 1/3 | Medium, 100 | 0 | 1/3 | d10 | Small border force. |
| Orc Warrior Horde | 1/3 | Huge, 500 | +4 | 3 | d10 | Large battlefield threat. |
| Troll War Band | 5 | Small, 50 | -2 | 3 | d8 | Fewer units, stronger bodies. |
| Knight Cavalry | Rider 2, Mount 3 | Large, 200 | +2 | 5 | d10 | Mount CR drives base value. |
Army CR Planning Guide
Why Army CR Matters
Army CR turns many creatures into one battlefield unit. It gives the game master a fast way to compare forces. A small band of elite monsters can equal a large group of weaker soldiers. This keeps mass combat simple. The calculator helps you see that balance before the battle starts.
Building Better Armies
Start with the creature that represents most soldiers. Do not use the strongest hero in the force. Use the common unit. Then choose the army size. Size changes ACR by steps. A Medium army has no size adjustment. Larger armies move upward. Smaller armies move downward.
Reading the Combat Values
Offense Modifier shows how hard the army hits. Defense Value shows how hard it is to damage. Hit points show staying power. Consumption shows the cost of keeping the army active. These numbers help you plan sieges, marches, ambushes, and defensive stands.
Using Bonuses Carefully
Commanders, tactics, resources, terrain, fortifications, and settlement defenses can change the result. Add only bonuses your table actually uses. Keep notes beside each army. Clear notes prevent confusion during long campaigns.
Balancing Encounters
Compare your army ACR with the enemy ACR. Close values make tense battles. A difference of several points can create a one-sided fight. Terrain can still change outcomes. Ranged attacks, poor morale, and strong fortifications may matter as much as raw ACR.
Exporting Battle Records
Save results before a session. CSV files work well for spreadsheets. PDF files work well for table notes. Keep one file for each army. This makes recurring wars easier to manage.
FAQs
What does ACR mean?
ACR means Army Challenge Rating. It represents the overall battlefield strength of a mass combat army.
Which creature CR should I enter?
Enter the CR of a typical army member. Do not use a rare officer unless that officer represents the whole unit.
How does cavalry work?
When cavalry is selected, the calculator compares rider CR and mount CR. It uses the higher value as the base CR.
Why does army size change ACR?
Larger armies gain steps on the CR scale. Smaller armies lose steps. This models the effect of unit count.
Can I use decimal bonuses?
Yes. The form accepts decimal bonuses for custom tactics, strategy shifts, commander effects, and table variations.
What if the result is below 1/8?
The force is too small or weak to count as a formal army. Add more units or use stronger creatures.
Does morale always affect OM?
Not always. This calculator lets you add morale as an optional OM adjustment. Set it to zero when unused.
Can I export the result?
Yes. After calculation, use the CSV button for spreadsheet data or the PDF button for printable campaign notes.