All games of the Hitman series present players with choices in carrying out the game's missions. Players can perform precise assassinations or be incredibly brutal in their own approach to achieving mission goals; however, the game rewards the more subtle approach by giving special weapon rewards or cash bonuses when players achieve the Silent Assassin rank (usually achievable by eliminating only the mission's target, and without raising the alarm doing so). The Hitman games, although brutally violent at times, discourage reckless bloodshed and the player is penalized with lower pay should innocent blood be spilt (Although "accidents" don't count).

Level and mission design is generally non-linear, in that missions have an exploration element to them and generally do not proceed along a single fixed path; however the order of missions is always completely linear in every game.

The gameplay revolves heavily around disguises, which the player uses to fool enemies and gain access to restricted areas. The focus of the Hitman series is not hiding in the shadows from the enemy, but rather blending in amongst them (although sneaking behind guards and avoiding patrols becomes more prevalent in the gameplay of later games).

The player's character, Agent 47, is not particularly maneuverable; he cannot jump at all, let alone scale walls or mantle up ledges (there are a couple of pre-scripted places where he can jump from one balcony to another, but these are rare); however more maneuverability is available in the latest game in the series, Hitman: Blood Money. This generally limits the player to a single plane of movement, although he is often presented the opportunity to move to higher or lower areas through the use of ladders, stairs, elevators, or hills.

A major feature in the game is the "alert" meter, detailing how much attention the player is receiving from the public or guards and is dependent on many things. For example, walking around in a guard's uniform with the correct corresponding gun won't gather much notice, whereas running around in a waiter's uniform in a restricted area while carrying a visible weapon instead of an appetizer tray will most likely result in an unwanted confrontation with the guards.

In terms of action, the Hitman series runs a middle ground between shooters and stealth games. Unlike most stealth game protagonists, 47 can survive considerable damage before dying. There is no "weapons free" prompt required, as in Splinter Cell. Combined with the game's impressive arsenal, this allows for some high-action firefights. At the same time, players were originally unable to heal 47's health in the middle of a level, which tends to encourage the player to avoid as much damage as possible. This is especially important in later levels, where enemies begin carrying high-powered weapons such as shotguns or sniper rifles that can kill 47 in one or two hits. Hitman: Blood Money was the first game in the series to allow players to purchase health-boosting items such as adrenaline and painkillers.

Many levels in the Hitman games can be completed without firing a single shot; this style of gameplay became more prevalent in Blood Money, where the focus was to make 47's hits look like accidents. Accidents can be caused remotely with RU-AP mines acting on some (usually heavy and suspended) object, directly by pushing someone over a railing, and by many other methods.