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 10^th 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

Standing Army type (following the reforms of Caius Marius) CR ❸, which based upon the number of army units i.e., 25 converts to a +20 Fighting Bonus (FB). They also get +1 to Initiative for Forced March. Battle Dice 2D6 (highest scoring die only). Fighting Technique: Legion which gives the Romans a +2/+4 modifier to their Battle Dice score for Heavy Infantry. The second modifier is used if FB greater than that of the opponent. Also, a Standing Roman Legion can save against defeat by rolling 4-6 on 1D6 which is owing to their Special Ability Relentless. The Romans also have Heavy Cavalry which gives them a 1D6+2 Advantage Die as well as the normal +1 to Initiative for cavalry. Due to combat experience in the Gallic Wars Caesar’s army has Veteran status which gives it a 1D3 Battle Advantage Die. 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

Mixed Army combination CR ❸/❶ (large number of foreign troops), which based upon the number of units i.e., 40 converts to a +22 Fighting Bonus (FB). A Mixed Army doesn’t get a +1 to Initiative for Forced March. Battle Dice 2D6 (highest scoring die only). Mixed Fighting Technique (MFT: Legion/Imitation Legion which gives the Romans a +2/+3 modifier to their Battle Dice score for Heavy Infantry. The second modifier is used if FB greater than that of the opponent. Also, a Mixed Roman Legion will suffer a -1 penalty to its Relentless saving throw. Pompey’s army also has Heavy Cavalry which gives them a 1D6+2 Advantage Die as well as the normal +1 to Initiative for cavalry. 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 determined by the army type and FB.

• 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.

Combat Rating to Fighting Bonus Conversion and Casualty Tables not shown.

Battle Log

Caesar’s Later Republican Roman Army

Initiative	Battle Dice (Modifiers)	CR to Fighting Bonus	Battle Bonus	Battle Advantage Dice	Total Score
2D6 +4 6 and 3 6+4 = 10	2D6 Legion (+2/+4) 5 and 2 (Highest die only) 5+2 = 7	❸x 25 = +20 FB Relentless 4-6	No odds or evens 3D6 6+4+2 = 12	Tactical Advantage 2D6 Heavy Cavalry 1D6+2 Veteran Status 1D3 5+3 +(3+2) +3 = 16	7+20+12+16 = 55

Pompey’s Later Republican Roman Army

Initiative	Battle Dice (Modifiers)	CR to Fighting Bonus	Battle Bonus	Battle Advantage Dice	Total Score
2D6 +1 4 and 5 5+1 = 6	2D6 MFT (+2/+3) 2 and 1 (Highest die only) 2+3 = 5	❸/❶x 40 = +22 FB Relentless 5-6 1D6 = 3	No odds or evens 3D6 2+2+5 = 9	Opponent outnumbered 1D6 Heavy Cavalry 1D6+2 5+(1+2) = 8	5+22+9+8 = 44

MFT = Mixed Fighting Techniques

Battle Bonus Calculation Table

FB	Warband	Feudal	Citizen	Part-Standing	Standing
1-4	1D3(1D6)	1D3(1D6)	1D3(1D6)	1D3(1D6)	1D6(2D6)
5-8	1D3(1D6)	1D3(1D6)	1D3(1D6)	1D6(2D6)	1D6(2D6)
9-12	1D3(1D6)	1D3(1D6)	1D6(2D6)	1D6(2D6)	2D6(3D6)
13-16	1D3(1D6)	1D6(2D6)	1D6(2D6)	2D6(3D6)	2D6(3D6)
17-20	1D6(2D6)	1D6(2D6)	2D6(3D6)	2D6(3D6)	3D6(4D6)
21-24	1D6(2D6)	2D6(3D6)	2D6(3D6)	3D6(4D6)	3D6(4D6)
25+	2D6(3D6)	2D6(3D6)	3D6(4D6)	3D6(4D6)	4D6(5D6)

(#D#) = Enhanced Battle Bonus on odds or evens Battle Dice.

For a Mixed Army Combination select the column to the left of the primary Army Type and use the bonus dice shown therein.

Note: - Caesar wins Initiative by 4 which yields a 2D6 Tactical Advantage. This is followed by an impressive Battle Bonus of 12 and 16 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. Pompey’s only chance is his Relentless roll for which he requires a 5-6 on 1D6. However, a 3 is rolled which means that rather than a refight or orderly retreat his army is routed. The result is a major victory for Caesar’s army that loses 5 units, whereas Pompey’s army ceases to exist.

Caesar’s legions clash with those of Pompey at the Battle of Pharsalus 48 BC. Figures by Essex 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. 

Sources

Boulter, M. L. 2009/2025: 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 13^th Twin Legion. After Alamy (IY04570615).