Single Missions are the first operations available, and the only missions available until you have achieved Squad Level 6.

There are 36 missions, ranging from single rooms to warehouse-sized complexes. Objectives primarily include Hostile Clearing, Hostage Rescue, and Arrests, which are indicated in the thumbnail gallery with symbols corresponding to each mission type.

Single Missions are intended to offer practice and variety. Most missions after the first few will allow you to select which squad members you wish to use, up to the maximum allowed number of officers, and to customize them as required. Squad injures and fatalities which occur during the mission are not permanent, and will revert as soon as the mission has concluded, successfully or otherwise. Officers used for the mission will receive experience upon successful completion, although no experience will be awarded in the event the mission is failed or aborted.

Missions 1-4 will automatically assign the first two officers in your original roster to the mission; changing the order of your roster later on will not alter the selections. Any equipment customization to these officers is also undone; they are given their initial, standard Pointman profile, although names and nickname changes will be reflected, as will rank. These first four missions are intended to be tutorial-like, though they are more open ended than standard tutorials. Inscriptions on the floor of the environment, or inserted as pop-up text, will instruct you on basics including movement, GO orders, grenade usage and door breaching.

Mission 5 and most subsequent missions remove any structured elements and simply start the player with a floor plan and a goal. This is the first mission in which you can select other team members from your roster, allowing you to build the experience of your other troopers. Equipment customization will also be observed.

Upon selecting a mission from the gallery, the player is given a slightly more detailed briefing, which consists of bulleted objectives and any conditions, as well as a larger blueprint floor plan and a tango count if the mission includes that element. The tango count is usually a range, with confirmed tangos represented with red profiles, and potential tangos displaying red profiles with question marks. The mission will always include at a minimum all confirmed tangos; potential tangos may or may not be present. This is determined as soon as the mission begins; potential tangos will not spawn during a mission.

Once the player begins the mission, they are brought to the main map in Deploy Mode. This mode is denoted by a yellow border along the bottom, and includes only the floor plan for the mission. In most missions the player is offered a starting point for their troopers; there may be multiple starting points, more than the allowed number of officers, allowing for multiple insertion options. The mission will automatically insert officers from the roster in order to fill the spots, starting wit the first trooper and proceeding. The player can alter this setup by dragging and dropping troopers from the map to the roster bar located along the top. Customizations including loadout changes can be made from the roster bar while in Deploy Mode.

Once the player is satisfied their officer selection, hitting the next button or space bar will advance the mission to Planning Mode. This is denoted with a red border along the bottom, and begins with the clock at 00:00. At this point the player is able to issue their initial orders to the troopers, including movement, facing and breaching. Hitting the next button or spacebar again will advance to Realtime.

Realtime is the state in which the action of the mission occurs. Troopers will execute their orders, and Tangos will move and shoot. Hitting the space bar at any time will pause the game and bring the player back into Planning Mode, allowing them to alter their orders or assess a development. This can be done even in the middle of a firefight. Orders can also be changed during Realtime, with officers executing new plans as soon as they are issued. With some practice, it is possible to walk a single officer through in Realtime, lending a 3rd person perspective and potentially improving response/reaction time, though all other officers will have to have scripted orders, offsetting this advantage.

The mission concludes when all primary objectives have been met, when one of the primary objectives is failed, or when all officers have been "killed". Upon successful completion of a mission, the player is shown the amount of Realtime it took to complete, SWAT casualties, Hostiles Incapacitated and the total XP earned. The player can select an option see the detailed stats, which offers a more through breakdown of the XP awarded. The player is also graded on a three-star scale, influenced primarily by the time taken to complete the mission, the injuries/fatalities endured by the SWAT team, and the degree of objectives completed successfully. Depending on the time used, the post-mission screen may also include a "Time to Beat", or the amount of time the mission should take when executed well. Surpassing the Time to Beat does not prevent you from successfully completing the mission, but will prevent a three-star score. If the player has matched or beaten the time, no "Time to Beat" is displayed, and the mission time is in green numbering.

A note on Experience: Once the mission has been successfully completed, the amount of experience earned by each officer is calculated. Even if the mission was a complete success, if the player chooses to "Restart" the mission, none of the experience is kept, and instead the entire situation reverts as though the mission had never been played. Only after selecting "Continue" or "Back" is the experience permanently applied to the trooper. So in order to grind out a single level, the player must back out in to the gallery in between each run.

In addition to a primary objective, such as clearing all hostiles or rescuing all hostages, most missions will also include one or more sub-challenges. These include awards for using only a single trooper, for using only a single plan of action without modifications, and for not pausing the mission after the initial planning stage, among others. They are not required to complete the mission, and do not contribute to the XP earned by your squad members.