Clash of Empires Legion against Legion The Battle of Pharsalus 48 BC

In this article I’m going to use the Clash Battle System to recreate the Battle of Pharsalus 48 BC. This battle was the turning point in The Great Roman Civil War between Caesar and Pompey 50 – 44 BC. It is significant because it pitted legion against legion in a campaign in which the outcome was decided more by discipline, experience and morale than just leadership and numerical strength.

Background

At the time of Caesar’s rise to fame Pompey was Rome’s leading statesman and a great conqueror in his own right. Formerly an ally of Caesar relations became strained as fear of Caesar’s intentions turned to enmity which would now plunge the Roman World into civil war. Rather than disband his legions Caesar marched on Rome. The speed of his advance from his base in Transalpine Gaul was such that Pompey was taken by surprise and along with a large part of the Senate was forced to abandon the capital. They withdrew to Greece and there raised an army of about 45,000 infantry and 5,000 cavalry from the eastern provinces. After securing Rome Caesar was quick to follow and with an army of about 30,000 infantry plus 1,000 cavalry confronted Pompey on the plain of Pharsalus. Both armies were deployed in the traditional manner of three lines each with a flank secured on the Enipeus River. Caesar positioned his elite 10th legion on the right flank and kept a hand-picked force of six cohorts in reserve which were positioned on the right rear.  As the two armies collided Pompey launched his cavalry against Caesar’s small contingent of cavalry, whereupon Caesar used his reserve to attack the flank of the Pompeian cavalry which was driven off. The six cohorts and Caesar’s cavalry then enveloped the left flank of Pompey’s main body. Caesar now moved up his third line which smashed into the front of the Pompeian legions who broke and ran. In this decisive battle Caesar’s army suffered about 2500 casualties whereas Pompey lost 15,000 killed and wounded and many thousands more taken prisoner. After the battle Pompey sought refuge in Egypt but was assassinated by his associates. Caesar arrived soon after and became embroiled in a dispute between the young Ptolemy XII and his co-ruler Cleopatra who was his elder sister. After making Cleopatra sole regent of Egypt Caesar returned to Rome which he ruled as a dictator until 44 BC when he was assassinated. At the time he was planning to avenge his old ally Crassus in a campaign against the Parthians.

Clash of Empires

Using the Clash of Empires rules the battle strength and capabilities of the belligerents can be shown as follows: -

Caesar’s Later Republican Roman Army

The Later Republican Roman army of Caesar consists of 25 units inclusive of cavalry. Following the reforms of Caius Marius, the Roman army is now a professional Standing army which uses 2D10 for its Battle Dice.  Due to combat experience in the Gallic Wars ten of the 25 units are classed as veteran Praetorian units with a Combat Rating of ❸. The rest of the Legionary army has a Combat Rating of ❷. A Standing Roman Legionary army also gets +1 to Initiative for Forced March. On the Combat Rating (CR) to Fighting Bonus (FB) Conversion Table a CR of ❸ equates to +8 FB for 10 Praetorian units and +7 FB for the other 15 ordinary Roman Legionary units. This gives a total of +15 FB which is added to the Battle Roll. For Battle Bonus calculation a Roman Legionary army gets a +2 modifier for close order infantry in melee. The Romans also have a Heavy Cavalry upgrade which gives them a +2 modifier for mounted impetus as well as the normal +1 to Initiative for cavalry. The Romans can achieve a Double Bonus if they roll odds or evens Battle Dice. Furthermore, a Standing Roman Legion can save against defeat by rolling 4-6 on 1D6 for Relentless. This can be used for a field battle and once only. If successful, the Roman army can fight again. In this refight any tactical or numerical superiority that either side might have is negated, but the Roman army will get a manipular support bonus of 1D6. In a refight situation the Battle Bonus percentage remains unchanged, but the Battle Bonus Dice are rerolled. If the Romans choose not to refight then they can disengage with 25% losses to the loser and 10% losses to the winner. At this advanced stage in his military career Caesar is ranked as a Great Commander and rolls 2D6 (Highest scoring die only) for Initiative. His army forged in the crucible of war has a superior command structure +2 Initiative. Therefore, the Later Republican Roman army of Caesar rolls 2D6 +4 for Initiative. Caesar’s army is significantly outnumbered by its opponent.

Pompey’s Later Republican Roman Army

The Later Republican Roman army of Pompey consists of 40 units inclusive of cavalry. Due to a high number of foreign troops Pompey’s army is classed as Mixed and thus uses a 1D10 and 1D6 for its Battle Dice and has an army ratio of 3:1. His army doesn’t get +1 to Initiative for Forced March. The primary army type is Standing Roman Legion and the secondary army type is Citizen/Feudal Imitation Legions which have been provided by petty Kings under Roman influence in the east. The Pre-generated Army Ratio Table in the rulebook shows that an army of 40 units in the ratio 3:1 will consist of 30 Primary Roman Legionary units and 10 Secondary Non-Roman Imitation Legionary units. All these units have a Combat Rating of ❷ which equates to +20 FB on the Combat Rating to Fighting Bonus Conversion Table. All Battle Bonus modifiers are as above. However, the Imitation Legions don’t have a saving throw against defeat and will cause a -1 penalty to the Relentless saving throw of a Legionary army that includes any Imitation Legions. (See above for Relentless rule). A conquering hero himself Pompey is ranked as a Great Commander and rolls 2D6 (highest scoring die only) for Initiative. However, his army due to its inexperience and mixed nature hasn’t got a superior command structure. Therefore, the Later Republican Roman army of Pompey rolls 2D6 +1 for Initiative. Pompey’s army outnumbers that of his opponent and gets a 1D6 numerical advantage.

Pompey’s Later Republican Roman Army

The Later Republican Roman army of Pompey consists of 40 units inclusive of cavalry. Due to a high number of foreign troops Pompey’s army is classed as Mixed and thus uses a 1D10 and 1D6 for its Battle Dice and has an army ratio of 3:1. His army doesn’t get +1 to Initiative for Forced March. The primary army type is Standing Roman Legion and the secondary army type is Citizen/Feudal Imitation Legions which have been provided by petty Kings under Roman influence in the east. The Pre-generated Army Ratio Table in the rulebook shows that an army of 40 units in the ratio 3:1 will consist of 30 Primary Roman Legionary units and 10 Secondary Non-Roman Imitation Legionary units. All these units have a Combat Rating of ❷ which equates to +20 FB on the Combat Rating to Fighting Bonus Conversion Table. All Battle Bonus modifiers are as above. However, the Imitation Legions don’t have a saving throw against defeat and will cause a -1 penalty to the Relentless saving throw of a Legionary army that includes any Imitation Legions. (See above for Relentless rule). A conquering hero himself Pompey is ranked as a Great Commander and rolls 2D6 (highest scoring die only) for Initiative. However, his army due to its inexperience and mixed nature hasn’t got a superior command structure. Therefore, the Later Republican Roman army of Pompey rolls 2D6 +1 for Initiative. Pompey’s army outnumbers that of his opponent and gets a 1D6 numerical advantage.

Clash Battle System

After rolling for Initiative the Battle Roll for each army consists of the following procedure:

• Roll Battle Dice (highest scoring die only)

• Plus, Combat Rating (CR) to Fighting Bonus (FB) (conversion dependent upon number of units)

• Plus, Battle Bonus calculation and Double Bonus if applicable.

• Plus, Advantage Dice (representing a numerical, tactical or other special advantage)

Highest score wins and the difference between the two Battle Rolls determines the number of casualties.

Conversion and Casualty Tables not shown.

Battle Log

Caesar’s Later Republican Roman Army

Initiative	Battle Dice	No. of Units and CR to Fighting Bonus	Battle Bonus	Battle Advantage Dice	Total Score
2D6 +4 6 and 3 6+4 = 10	2D10 9 and 2 (Highest die only) No odds or evens	25 Standing Roman Legionary units (6 legions) ❸x 10 = +8 FB ❷x 15 = +7 FB Total = +15 FB  Relentless 4-6	19 Points Converts to 2D6 4+2 = 6	Tactical Advantage 2D6 5+3 = 8	9+15+6+8 = 38

Battle Bonus Calculation Table

Battle Factor (1D6)	Modifiers	Score	Points Value
Shooting	0	4	4
Infantry Melee	+2 Close Order Infantry	5+2	7
Mounted Impetus	+2 Heavy Cavalry	6+2	8
			Total = 19

Roll 1D6 for each Battle Factor and apply modifiers to find total points value and then compare with total FB on the conversion table (in rulebook) to calculate Battle Bonus Dice. Can simplify by rolling 3D6 plus total modifier. Double bonus for odds or evens Battle Dice.

Note: - Caesar wins Initiative by 4 which yields a 2D6 Tactical Advantage. This is followed by a Battle Bonus of 6 and 8 on the Advantage Dice. Thus, after countering Pompey’s cavalry the surprise envelopment combined with the charge of the third line smashes the Pompeian army. The result is a major victory for the loss of 5 units.

Pompey’s Later Republican Roman Army

Initiative	Battle Dice	No. of Units and CR to Fighting Bonus	Battle Bonus	Battle Advantage Dice	Total Score
2D6 +1 4 and 5 5+1 = 6	1D10/1D6 2 and 1 (Highest die only) No odds or evens	40  Mixed Roman Legionary units  ❷x 40 = +20 FB Relentless 5-6 1D6 = 3	13 Points Converts to 2D6 2+2 = 4	Opponent outnumbered 1D6  = 5	2+20+4+5 = 31

Battle Bonus Calculation Table

Battle Factor (1D6)	Modifiers	Score	Points Value
Shooting	0	2	2
Infantry Melee	+2 Close Order Infantry	3+2 = 5	5
Mounted Impetus	+2 Heavy Cavalry	4+2 = 6	6
			Total = 13

Roll 1D6 for each Battle Factor and apply modifiers to find total points value and then compare with total FB on the conversion table (in rulebook) to calculate Battle Bonus Dice. Can simplify by rolling 3D6 plus total modifier. Double bonus for odds or evens Battle Dice.

Note: - Pompey loses Initiative and rolls very low on the Battle Dice only scoring a 2. Therefore, the cavalry is driven off and the main body of the Pompeian army enveloped. Pompey’s only chance is his Relentless roll for which is required a 5-6 on 1D6. However, a 3 is rolled which means that rather than a refight or orderly retreat his army is routed. In this crushing defeat Pompey loses 75% of his army which equates to 30 units killed, wounded or captured.

Caesar’s legions clash with those of Pompey at the Battle of Pharsalus 48 BC. Figures by Essex and Irregular Miniatures from their 25mm Ancients range. Painted by Silurian and from the author’s own collection. The numerical strength of each army is denoted by the coloured plastic counters. Game board from the Clash of Empires: The Hellenistic World Game.

Pompey’s position at the Battle of Pharsalus 48 BC becomes untenable as the left flank of his army is enveloped by Caesar’s Gallic cavalry and the six cohorts of the reserve. Figures by Essex Miniatures from their 15mm Ancients range. Painted by Silurian and from the authors own collection. Army composition calculated by the Clash Conversion Table for Wargaming.

Sources

Boulter, M. L. 2009/2024: Clash of Empires: The Hellenistic World. Silurian War Games Ltd.

Dupuy, R. E. and Dupuy, T. N. 1993: The Collins Encyclopaedia of Military History. Harper Collins Publishers.

Hackett, J. 1989: Warfare in the Ancient World. Sidgwick & Jackson Ltd.

Jimẻnez, R. L. 1996: Caesar Against The Celts. Spellmount Limited.

Mellersh, H.E.L. 1995: Chronology of the Ancient World, 10,000 BC – AD 799. Helicon Publishing Ltd.

Article Front Page Picture

Julius Caesar crossing the Rubicon in 49 BC with the 13th Twin Legion. After Alamy (IY04570615).