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This article is accurate for the latest versions of EU3, Napoleon’s Ambition and In Nomine v3.2.
Please help update this page to include information on the HTTT and DW expansions.

Siege is the military method of taking a fortified province from a nation. A siege begins automatically when you alone occupy an enemy province.

You may elect to end the siege faster by committing to an assault by clicking the appropriate button within the siege status screen, but it will come at a high cost to your troops. The chances of a successful assault are greatly increased when there is a Breach in the walls.

Every month after your troops begin besieging a province, the game will check to determine the siege's progress.

In In Nomine, sieges and assaults may be shorted or prolonged based on the province's defensiveness bonus.

Artillery Bonus

Adding artillery to a besieging army gives a bonus and makes the siege progress faster.

  • 4 artillery regiments per fort level = +3
  • 3 artillery regiments per fort level = +2
  • 1-2 artillery regiments per fort level = +1

Siege Success Calculation

Siege formula is:

1D10 - effective fort level + siege value of general + Artillery bonus + siege progress

Effective fort level: Fort level + (fortlevel * defensiveness) Siege progress: +1 per 12,5% progress (up to 8 max)

Example: Level 4 fort with 50% defensiveness is besieged by 4,000 Artillery under a 2 point siege general, siege progress is 50%:

1D10 - 6 (eff. fort lvl) + 2 (siege val general) + 1 (Artillery bonus) + 4 (siege progress) = 1D10+1

Required dice result for fort surrender is 12+ or 13+


Leaders  • Maintenance  • Morale  • Manpower  • Ship types (Big ship  • Light ship  • Galley  • Transport)  • Land unit types (Infantry  • Cavalry  • Artillery)  


Assault  • Basic Warfare  • Casus Belli  • Combat • Making peace • Siege • Supply & attrition • War Capacity  • War Exhaustion