Missions

In the organised society of the villages, ninja are given of varying difficulty depending on their skills. Several different kinds of requests come into a village (either from within the village or from an external source). These requests are officially recorded, analyzed and then categorised (by the concerned authorities) into one of the five ranks, based on the mission's possible danger or level of importance.

Perception on Missions
Depending on the importance and nature of the mission, as well as the regards of the village head, failure could result in variable consequences. While Shikamaru Nara failed to retrieve Sasuke Uchiha, the Fifth Hokage gave him words of comfort and support. On the other hand, when Sakumo Hatake botched a very important mission by choosing to rescue comrades over completing it, he was heavily dishonoured throughout his village and country, which eventually drove him to commit suicide. In Takigakure, failure of a mission brings very harsh consequences, as Kakuzu's failure to assassinate Hashirama Senju led to an unfair imprisonment despite the insurmountable danger involved, a treatment that led to his revolt. As such, certain villages put missions to a higher priority than others, as Sunagakure would choose accomplishing missions over the lives of their comrades, Iwagakure would follow orders even if it means death and Konohagakure's Shinobi Rules #4 states that "A shinobi must always put the mission first".

Because of the importance of missions, certain shinobi would take even the most drastic (sometimes considered illegal) actions to ensure its completion, even if it means sacrificing comrades, as Kisame Hoshigaki and Mizuki did. This may lead to certain controversies to the shinobi with their associated villages, depending on the situation. Kisame was simply following his superior's ideology and orders and was complimented even by the Fourth Mizukage for his willingness to make such sacrifices for Kirigakure. Mizuki, on the other hand, killed a slightly injured comrade simply to eliminate any potential hindrances, and falsified the reason of death, which led him to be ostracised based on the suspicious circumstances of this transgression.

Mercenary Ninjas accept missions from clients just as much as village-bound ninjas. However, these missions are considered more illegal, as they can involve assassination of people that are normally not meant to be targeted (such as Kisame Hoshigaki killing a daimyō), or creating acts of terrorism (such as Deidara becoming an insurgent bomber for anyone who would hire him). These missions are not ranked as they are not handed out by an official system. Clients may hire mercenaries instead of legal ninjas for shady businesses (such as Gatō) or cheaper prices (as Akatsuki offered).

The prices of missions can affect the client's decision on who to employ and how. Tazuna and Haruna downplayed their missions' details and dangers due to their inability to afford higher prices. Gatō hired Zabuza Momochi's group of renegades, who charge high prices, but would betray them with a large mob of less expensive mercenaries to prevent paying these excessive fees. Akatsuki intended to cause economic declines in shinobi countries by charging missions at much lower prices that villages cannot afford to. Even countries would hire services from foreign forces if it means saving a budget, as the Wind Daimyō outsourced many missions to Konohagakure over his own country's Sunagakure, and Ōnoki hiring Akatsuki many times for missions.

If the client who hires ninjas for a mission gives false information on details, such as downplaying the dangers involved (which in turn becomes a mission that exceeds the expectations of its corresponding rank), the ninja in question will no longer be obligated to complete the mission (though they may continue if they choose).

Mission Ranks

 * D-rank - assigned to genin fresh from the Academy. They pose almost no risk to the ninja's life and usually consist of odd jobs like farming, helping someone in shopping and babysitting work. The reward for a D-rank mission is between five thousand and fifty thousand ryō.
 * C-rank - assigned to more experienced genin or chūnin. They are missions with little to no chance of combat against other ninja. Examples are guarding people against bandits or highwaymen, background investigations, eliminating or capturing bandits or thieves, and capturing or suppressing wild animals. The reward for a C-rank mission is between thirty thousand and 100 thousand ryō.
 * B-rank - assigned to experienced chūnin. They are missions anticipated to involve combat with other ninja. Examples are guarding people, espionage, or killing other ninja. The reward for a B-rank mission is between 150 thousand and 200 thousand ryō.
 * A-rank - assigned to jōnin, concerning, among other things, village-or state-level matters and trends. Examples are guarding VIPs or suppressing ninja forces. The reward for an A-rank mission is between one hundred fifty thousand and a million ryō.
 * S-rank - assigned to experienced jōnin and concern state-level confidential matters. Examples are assassinating VIPs, and transporting highly classified documents. The reward for an S-rank mission is more than a million ryō.

Trivia

 * Although Hiruzen, explaining to Naruto the classification of missions, mentioned upto A-rank, there have been several occurrences of S-Rank missions.