[12] Europa Barbarorum retains this basic gameplay mechanic and sets itself in a similar time period and geographical area to the original game.

So, for example, Rome: Total War's trait-acquisition system, where the player's faction's family members acquire certain characteristics and talents which make them more or less adept at certain tasks such as city management or military leadership, has been made more faction-specific in Europa Barbarorum, with Hellenic characters' traits, for instance, being based on Theophrastos' Characters and Aristotle's teachings on the Golden Mean, and Romans' traits being partially based on the moral tales of Valerius Maximus.

[13][21] There are sometimes additional requirements for a family member to be able to gain a new trait: in order for them to compete in one of the Panhellenic Games, for instance, the player must ensure that they are stationed in the appropriate city on the campaign map in the year that the competition is scheduled to take place.

[13] One reviewer has commented that Europa Barbarorum's expansions upon the original Rome: Total War's trait system have served to add a role-playing element to the game.

A key game mechanic of the campaign map is the annexation of territory, which is done province-by-province, either by successfully besieging the province capital, or by acquiring it from another faction through diplomacy.

The process of assimilating a newly conquered province into one's empire has become more differentiated in the modification than it was in the original game through the introduction of so-called "government buildings"[27] and military–industrial complexes.

Troops can either be killed outright on the battlefield or made to rout and flee the field if their morale falls below a certain threshold.

Reviewers have noted of Rome: Total War that, during a battle, troop numbers do not outweigh all other considerations; other factors such as individual unit types' strengths and soldiers' morale and fatigue at the point of fighting are also taken into account.

[3] Specific examples include the removal of several units that the Europa Barbarorum team considered to be historically doubtful or only marginally used in warfare, such as Arcani,[26] incendiary pigs and Celtic head-hurlers from the original Rome: Total War.

[22][33] This was followed by version 1.1, which was released in April 2008[22] and included new battle map landscapes, new units, the addition of the Pahlavi voicemod and the inclusion of an introduction video for the Saka Rauka faction.

[16] Earlier releases of Europa Barbarorum also featured player alerts representing the major stages of the breakup of the Seleukid faction, if that collapse occurred in the game.

[13] However, such features became impossible to implement after the SPQR faction of the original game, used in Europa Barbarorum for scripting purposes, was removed from the mod in exchange for the kingdom of Saba.

[22][43][44] Europa Barbarorum II includes new government, unit recruitment and trait systems,[22][41] and new playable factions such as the kingdom of Gandhara, which has its own Sanskrit voicemod.

The Italian PC Gaming magazine Giochi per il mio computer reviewed the modification in April 2005[5] and March 2008.

[7] The 2005 review reported that the modification, whose development team included two historians, was to replace the "economic system, [soldiers'] equipment and the provinces" of Rome: Total War;[5] the latter review praised the mod for having "altered and deepened" the gameplay of the original title, and wrote that Europa Barbarorum was the best substitute for a Rome 2: Total War game prior to the actual release of such a title.

[7] Dutch magazine PC Gameplay [nl], reviewing the mod in March 2008, also wrote that the mod was "perhaps the best candidate for the title Rome: Total War II" "until the official announcement" and went on to note that the list of changes that the modification had made to the original game almost constituted "a history book of its own".

[9] The German magazine GameStar wrote in April 2007 that the Europa Barbarorum team had "banned all historical mistakes from the game";[25] in January 2011, another German publication, PC Games, also noted the mod's historical accuracy, singling out its "more realistic, more [challenging]" battles for praise, although it did note that the mod was squarely aimed at experienced Rome: Total War players.

[27] Reviewing version 0.74 of the mod in November 2006, Romanian publication LeveL concurred that the mod was aimed at experienced players, adding that the modified version of the game put greater demands on the player's computer than the original Rome: Total War, requiring 512 MB of RAM,[30] up from the original's 256.

[22][24][26] The modification received a review early into its development process on gaming website HeavenGames, which said that it was an "ambitious" project and praised its commitment to historical accuracy, even stating that the Europa Barbarorum development team was going to use satellite imagery and climate change statistics to accurately portray the world as it was in 272 BC.

[22] The modification has sometimes been mentioned as a recommended complement to Rome: Total War in reviews of the original title – for instance, by Norwegian gaming website Gamereactor in 2007.

[46] In addition, Europa Barbarorum was singled out for praise by the Creative Assembly themselves in 2011, when they called the mod "breathtaking" in an official[47] statement.