Combat in Eve is a mixture of both tactical intelligence and spontaneous decision-making using a point-and-click interface. While every race has certain tendencies for different battle tactics, a character's combat capabilities are determined by skill levels, the ship being piloted and various hardware modules fitted into it. Outside of decisions involving targeting and selection of weaponry, combat is, to a certain degree a 'hands off' affair, the player decides on the targets, distance they want to keep their target at, the speed of their ship and the weapons and modules to use, and once activated the computer runs these tasks until the player intervenes. An extreme example of this is that a ship set to repair itself without running its capacitor out, with a strong tank and drones set to aggressive can perform entire missions without any intervention from the player at all, past initial deployment to the battlefield. However on the other end of the scale players will often find that in pvp they are required to play a massive role in their ships operation, as they will be giving/ following orders, switching targets, maintaing locks/ dps or tackle while repairing damage and controlling speed, range and any other number of ships functions. There is a basic ability to freely direct your ships flight by double clicking empty areas of space, but it is cumbersome at best, so most movement is conducted by selecting objects in space (player or NPC ships, asteroids, structures etc.) and telling the ship to approach ,orbit or warp if the distance is greater than 150 km.

Eve's combat system allows ships of all sizes to be useful in combat. Large ships such as battleships are typically outfitted with heavy weapons allowing them to battle other ships of their size. Such weapons however do not have the accuracy to effectively damage smaller, faster ships like frigates.[17] While a large ship can equip smaller weapons designed for attacking smaller targets, this leaves them at a disadvantage against other large ships. Drones can also be used against smaller ships, or in a support role such as providing extra shield for a gang mate or in a utility role such as electronic warfare. Small ships such as frigates may be unable to do significant damage to larger ships on their own, but can greatly affect the outcome of small group battles by employing tactics such as "tackling" (disrupting the engines or guidance computers of enemies thus reducing mobility or chance to escape), jamming enemy sensors, or attacking a larger ship as a pack.

The open player versus player combat system, and the tendency for ships to drop some of their cargo and equipment when destroyed, provides incentive for player piracy. Pirates risk being branded criminals by CONCORD and thus becoming open targets to all other players, as well as being unable to access high security systems. Players may even place a bounty on another player's head, providing work for bounty hunters. 

At the strategic level, the rich resources available in low security space reward large co-operative groups. Usually formed when several player-owned-and-operated corporations (similar to guilds, in other MMORPGs) band together, these "alliances" can vary widely in size and strength. The network of jumpgates, which allows travel between star systems, includes a multitude of choke points, which careful alliances can garrison to restrict access to claimed 0.0 systems. Moreover, corporations and alliances have the ability to manufacture Player-Operated Starbases (POS) that mine resources from moons in a system. Each POS requires substantial logistical support to remain in operation, but once an alliance mounts and maintains such facilities at the majority of moons in a system, it achieves the status of sovereignty and remains so until an enemy destroys enough POSs and replaces them with its own.[19] Note that the sovereignty system has been dramatically changed as of the Dominion expansion, where now sovereignty is no longer held with the POS moon bases but instead held by Territorial Claim Units (TCUs)