My description of the process was getting too detailed and spoiling the narrative of the previous post:
https://onesidedminiaturewargamingdiscourse.blogspot.com/2025/10/lusitanians-versus-romans-and.html
I am working on a set of siege rules for use in campaigns but also as an after-battle adjunct for Basic Impetus games. They are based on the siege rules that are in the boardgame The Kingdom of Heaven.
The first step is to take stock of the remaining forces.
Lusitanians (the besieged)
- LC VBU 3 reduced to 2
- FL VBU 4 reduced to 1
- FL VBU 4 reduced to 1
- S VBU 3 still fresh
- S VBU 3 reduced to 1
- Commander was killed
Romans
- CM VBU 4 reduced to 3 with Commander
- FP VBU 6 reduced to 5
- FP VBU 5 reduced to 1
- FP VBU 6 still fresh
- FP VBU 6 reduced to 2
- S VBU 2 still fresh
- S VBU 2 still fresh
The siege system needs a calculation of number of units, steps, manpower and combat strength.
The Lusitanians have 5 Units the Romans 7. For the Romans this represents a significant force which required them to have more than 6 units.
The Lusitanians have 6 Steps and the Romans 10. Steps are calculated as 2 per fresh unit and 1 for a worn unit (regardless of losses).
The Lusitanians have 7 Manpower and the Romans 18. Manpower varies between 0 and 4 and calculated as the units VD plus 1 if the unit is fresh, minus 1 if the unit is mounted. The Lusitanian FL are VD 2 and the rest VD 1. The Roman FP are 3 VD, the CM 2 VD (which includes the Commander) and the S are 1 VD.
As the Roman's Manpower at least matches that of the Lusitanians a siege can be initiated.
The Combat Strength is the sum of the units' VBUs. The Lusitanians have 8, the Romans 21.
The next process is to calculate the Resistance Factor (RF) of the Stronghold into which the defeated Lusitanians have retreated. Obviously, a very campaign-based thing, but simply put Strongholds are either Wall Cities or Forts (Castles). Forts are more for campaigns so I will ignore the distinction and just go with the generic term Stronghold. Every Stronghold has a base RF of 3. As the Lusitanians have more than 2 Steps the RF is increased by 2 to 5. If the Stronghold was a port (either sea or major river) the RF would be increased by 1. Let's assume it is not and for imaginative purposes the battle took place near Óbidos. The Lusitanians have lost their Commander so there is no Leader bonus to the RF.
The Lusitanian Stronghold has a RF of 5.
The Romans can call for surrender. There are various campaign factors that may come into this, but simply in this case the Romans, on a D6, need to roll higher than the RF.
Assuming the Lusitanians don't surrender or that the Romans don't call for a surrender the next step is to see if the Romans can blockade the Lusitanian Stronghold. Blockade is achieved by comparing the besieging Manpower to that of the garrison. Each sides rolls a D6 and adds that to their Manpower. The besieger also adds one per cavalry unit that they have. If the besieger’s result exceeds that of the defender a Blockade is successfully implemented.
The Romans can easily establish a Blockade.
The siege is now established.
Each side receives seven siege event cards. I have taken these from the game Kingdom of Heaven which is here I got the idea and system for this siege process. Their deck has 60 cards. Of these 40 are can only be used by the attacker, 3 by both and 17 for the defender. There are 11 cards with a diplomacy value and range in value for -2 to +2.
Each card has an Operational Points value; an indicator of whether it is for the Attacker, Defender or Both; a possible Diplomacy Value; and an Event with any associated prerequisite.
The siege lasts as long as there are cards to play.
If the siege is not successful by the time all the cards are used, then the siege is over and the attacker withdraws. For a campaign game other options can obviously be considered.
Starting with the attacker/besieger a Siege Round is conducted by playing a card.
A Siege Round consists of one of four actions:
1. Starvation attempt (only if stronghold blockaded)
2. Call for Surrender (using a card with a diplomacy value)
3. Siege event (as per the card)
4. Fortunes of war
After one of the above actions is complete there is the option to perform an Assault.
Starvation is made by rolling on the Starvation/Attrition table using the Ops value of a card marked as Attacker or Both as a die roll modifier and the result being the number of steps lost.
A call for surrender requires a card with a diplomacy value and marked as Attacker or Both. The card's diplomacy value is used to modify the die roll.
A siege event is as described on the card. The attacker can only use events on cards marked as Attacker or Both. If they play a card marked as Defender, nothing happens (sieges can be boring). In their turn the defender can only use events on cards marked as Defender or Both. Some events have prerequisites or conditions.
Fortunes of War is available for the attacker by discarding a card in their hand. A random card is drawn and its event takes place regardless of Attacker Defender.
When a card is played the opponent may be able to play a card to cancel or alter the action.
Some cards provide for an additional card to be drawn.
With hopefully the process adequately explained, let's get on with the siege!
A random draw has the Romans holding:
#4 Ops=1 Attacker No Diplomacy "Lines of Circumvallation" Manpower required 3 "You may make a blockade roll if Stronghold is not a port. Or play to cancel Sortie by Besieged."
#16 Ops=1 Attacker No Diplomacy "Lines of Circumvallation" Manpower required 3 "You may make a blockade roll if Stronghold is not a port. Or play to cancel Sortie by Besieged."
#34 Ops=2 Attacker 0 Diplomacy "Battering Ram" Manpower required 1 "Reduce defender RF by 2."
#37 Ops=2 Attacker No Diplomacy "Fleets Blockade Stronghold" Only if fleet is available.
"Play to blockade any port and reduce its RF by 1. Draw replacement card."
#43 Ops=3 Attacker No Diplomacy "Rats in Enemy Food Supply" "Reduce defender RF by 2 and reduce up to three fresh units in the stronghold to worn if it is blockaded. Draw replacement card."
#46 Ops=3 Defender No Diplomacy "Traitor In Enemy Ranks" Increase RF by 2 as countermeasures are taken. Draw replacement card.
#55 Ops=3 Attacker No Diplomacy "Fleets Blockade Stronghold" Only if fleet is available.
"Play to blockade any port and reduce its RF by 1. Draw replacement card."
The Lusitanian hand is as follows:
#11 Ops=1 Attacker No Diplomacy "Fill in Defender's Moat" Manpower required 3 "Reduce defender RF by 1."
#20 Ops=1 Defender No Diplomacy "Blockade Broken" Make combat roll for garrison (no modifiers). Opponent takes casualties (but there's no determination of victory). If one or more step losses inflicted remove any blockaded marker. Draw replacement card. A blockade need not be in place for this card to be played.
#25 Ops=1 Attacker +1 Diplomacy "Ladders and Mantlets" Manpower required 1 "Reduce defender RF by 1."
#28 Ops=2 Defender No Diplomacy "Countermines" Manpower required 2 "Play to cancel Sappers and Miners."
#33 Ops=2 Attacker No Diplomacy "Severed Heads Tossed Into Enemy Stronghold" Manpower required 1 "Roll a die: 1-3 reduce defender RF by 1; 6 increase RF by 1. Draw a replacement."
#36 Ops=2 Attacker No Diplomacy "Fleets Blockade Stronghold" Only if fleet is available. "Play to blockade any port and reduce its RF by 1. Draw replacement card."
#56 Ops=3 Attacker No Diplomacy "Sappers and Miners" Manpower required 4 "Reduce defenders RF by 3."
Round One
The Romans play "Rats in Enemy Food Supply" which reduces the resistance factor to 3 and the Lusitanians lose 1 step and their combat strength drops to 7.
This event also provides for a new card to be drawn and the Romans add the following card to their hand:
#3 Ops=1 Defender No Diplomacy "Sortie by Besieged" Manpower required 1 "Commit up to two steps to attack. Roll 1 die for each: 1-3: committed step is lost; 4-6: increase RF by 1. Draw replacement card."
The Lusitanians play "Blockade Broken" This event gives them a free roll on the Assault table. They roll a 3 on a D6 and add two as the besieged force and cross reference 5 on the 7-10 column. The Romans suffer 2 step losses which they take on the two fresh S units. They drop to 8 steps, 16 manpower and 19 combat strength, but still have 7 units.
This event also provides for a new card to be drawn and the Lusitanians add the following card to their hand:
#12 Ops=1 Attacker No Diplomacy "Fill in Defender's Moat" Manpower required 3 "Reduce defender RF by 1."
Round Two
Angered the Romans play "Battering Ram" reducing the resistance factor to 1 and the Romans make an assault. The Romans have 19 combat strength and are on the 11-16 column having been shifted left by the residual RF of 1. They have a commander who adds 1 to the D6 roll which was 4 thereby becoming a 5 and inflicting 3 step losses on the Lusitanians. The Lusitanians are on the 7-10 column but throw a miserable 1 but have a +2 as the besieged. They inflict 1 step loss on the Romans. As the Romans caused double the number of step losses than they received it is a major victory and the stronghold is taken, the siege is over.
Conclusion
This siege played out very quickly. The Romans had some good cards, but the critical thing was the very poor roll by the Lusitanians. Anything but a 1 would have denied the Romans a major victory and the siege would have continued.
I will continue to develop the rules and conduct more test games.
These rules are based on the siege mechanics in the boardgame Kingdom of Heaven. The rules and cards for which can be found on Boardgame Arena:
https://boardgamegeek.com/boardgame/25900/kingdom-of-heaven-the-crusader-states-1097-1291
