Resources

Resources are needed for developing Provinces and training units. Three of them – Wood, Iron and Stone – are produced by resource-generating buildings: Lumber mill, Iron mine and Stone quarry. The resource output can be increased by upgrading the three resource-generating structures, so that new work vacancies are created and, thus, the possibility for increased production.^[7] The fourth main resource is Gold. It is used for almost any type of research, military training and building development. It is also the universal currency for buying and selling all three other types of resources. Gold is gathered through taxes, selling resources on the Marketplace, fortress sieges, deposit interests, and as one of the possible rewards from the various caskets awarded in the game. There are also the so-called 'Special resources' that can be found throughout the realm. There are more than 50 types of special resources and their main purpose is granting bonuses to various in-game statistics like resource production, military units, experience gain, etc.^[8]

Buildings

There are 29 structures that can be built and upgraded in the capital. Buildings are constructed and upgraded through a main building, called Town hall. The Town hall is the building every player starts the game with. The two main types of buildings are separated in tabs 'Economy' and 'Military'. Each building has a special function. For example, the two universities that make possible the development of Military and Economic technologies.

Provinces

Each Province starts as a single village that the player takes control of. Through building, research and battle progression the Province grows on the Global map, later annexing territories that turn into provinces of the original one, known as a Capital by that time. The development of the provinces is similar to what the player has gone through with the capital – buildings have to be built and upgraded, the population has to be predisposed to growing and kept happy and the resources and military units can be used by the entire Province. There are some disadvantages that provinces have compared to the Capital: universities for example can't be constructed on Province territory, same goes for the Palace, Headquarters, Gubernatorial headquarters, Bank, Wonders and so on. Colonization is one of the ways to expand your Empire's territory on the Global map.

Alliances

The Alliances in Imperia Online are groups of players sharing their own strategy with each other. Alliance members donate resources into the alliance treasury, which are used for researching technologies, waging wars, building alliance holdings, cultural and military influence expansion, etc. Allies can support each other in an economic and military way via gold transfer module. Alliances are ranked in a separate ranking based thoroughly on the total sum of all members’ net worth points.

Battles

Imperia Online's battle system is rich and complex, despite being built with five main types of military units only. The five main categories of units are Swordsmen, Spearmen, Archers, Cavalry and Siege Engines. The battle system requires skill, tactical thinking and the usage of the correct battle formation, as each battle's outcome is determined automatically upon the impact and the armies cannot be controlled directly.^[9] There are three types of attacks: Field Battle, Fortress Siege and Pillage. The first one sends the troops to fight only with the opponent's field army, without sieging the Fortress or pillaging the civil population. The only profit for the attacker are military points for slashing enemy units and honor points. Fortress siege is conducted after a successful Field battle for the attacker. A successful Fortress siege loots resources. If the player chooses Pillage, their troops engage the opponent's civil population. Gold is earned for every killed villager. It's punished with Honor drop.

The Great People

The Great People feature was introduced with the eponymous Version 6 of the game. It added the concept of Noblemen – the Emperor and his court, which can gain experience and level up in two distinct disciplines. The Governor skills generally boost the resource and troop production in a province, while General skills improve your battle capabilities. Furthermore, each of the Great People comes with their own inborn talents, and a careful selection of one's Emperor's hereditary line allows you to always keep the crown in the hands of the most suitable people. In 2018 Dungeons were introduced in the game. If a battle is lost by the player there is a chance their general to be captured by the opposite army.

Winning the Realm

Since the start of the version 5 of the game the winner of the Realm was determined by the Alliance competition. During that competition the alliances were trying to conquer the castles and control the influence these castles were projecting. At least 60% influence of the entire Global map territory for a set number of hours (depending on the speed of the Realm) were required, so a victory could be secured.^[10] After the Alliance winner in the competition had been determined, the era was finished.

As of 2016 all the eras in all realms of Imperia Online finish on a fixed date, announced in front by the game system. The winner of the Realm is the Alliance that has the highest percentage of influence up to that final date or the highest allied net worth points value, if no one has influence.

Global Events

The Global Events are epic challenges which Imperia Online offers to its players. The colossal structures have appeared for the first time in Version 6 and require an enormous amount of skill to be defeated. The Dark Fortress, The Skull of Wonders, The Tower of Knowledge and The Eternal Castle are just part of the events, which unite entire realms to conquer them.

Hall of Fame

In 2018 Hall of Fame was introduced. The feature contains the history of all eras in all realms of Imperia Online in the last decades. Each visitor of the main page is able to browse the game's entire history and see who were the top performing players and alliances even for a specific realm.