Both parties had made alterations in their military system.

Pyrrhus, perceiving with the sharp eye of a soldier the advantages of the Roman manipular organization, had on the wings substituted for the long front of his phalanxes an arrangement by companies with intervals between them in imitation of the cohorts, and-- perhaps for political no less than for military reasons--had placed the Tarentine and Samnite cohorts between the subdivisions of his own men.

In the centre alone the Epirot phalanx stood in close order.

For the purpose of keeping off the elephants the Romans produced a species of war-chariot, from which projected iron poles furnished with chafing-dishes, and on which were fastened moveable masts adjusted with a view to being lowered, and ending in an iron spike--in some degree the model of the boarding-bridges which were to play so great a part in the first Punic war.
According to the Greek account of the battle, which seems less one-sided than the Roman account also extant, the Greeks had the disadvantage on the first day, as they did not succeed in deploying their line along the steep and marshy banks of the river where they were compelled to accept battle, or in bringing their cavalry and elephants into action.

On the second day, however, Pyrrhus anticipated the Romans in occupying the intersected ground, and thus gained without loss the plain where he could without disturbance draw up his phalanx.