Conflict in strategy games takes place between groups or singular combatants, usually called units. Games vary in how many types of units a player can use, but each unit has specific strengths and weaknesses. Units vary in their movement and speed, as well as the amount of health or damage they can withstand. Units may also have different levels of attack strength or range. Although units are typically used for combat, they may also be used for other purposes such as construction, transport and scouting. Units that cannot move such as fixed turrets are often still treated as units. If a unit is destroyed, the player loses the benefit of that unit. Most strategy games allow players to construct new units in buildings or factories.
The player commands their forces by selecting a unit, usually by clicking it with the mouse, and issuing an order from a menu. Keyboard shortcuts become important for advanced players, as speed is often an important factor. Units can typically move, attack, stop, hold a position, although other strategy games offer more complex orders. Units may even have specialized abilities, such as the ability to become invisible to other units, usually balanced with abilities that detect otherwise invisible things. Some strategy games even offer special leader units that provide a bonus to other units. Units may also have the ability to sail or fly over otherwise impassable terrain, or provide transport for other units. Non-combat abilities often include the ability to repair or construct other units or buildings.
Even in imaginary or fantastic conflicts, strategy games try to reproduce important tactical situations throughout history. Techniques such as flanking, making diversions, or cutting supply lines may become integral parts of managing combat. Terrain becomes an important part of strategy, since units may gain or lose advantages based on the landscape. Some strategy games such as Civilization III and Medieval 2: Total War involve other forms of conflict such as diplomacy and espionage. However, warfare is the most common form of conflict, as game designers have found it difficult to make non-violent forms of conflict as appealing.