The Code of a Warrior Cat, as of River, A Starless Clan

1. Defend all the Clans, even with your life. Your first loyalty is to your Clan, but all cats who follow the warrior code are your allies. Each Clan must ensure that no other Clan falls.
2. Nevertheless, each Clan is proud and independent, with traditions that must always be respected.
3. An honorable warrior does not need to kill other cats to win their battles, unless they are outside the code, or it is necessary for self-defense.
4. Elders, queens, sick or injured cats and kits must be fed before apprentices and warriors. Unless they have permission, apprentices may not eat until they have hunted to feed the elders.
5. A Gathering of all five Clans is held at the full moon during a truce that lasts for the night.
6. No warrior can neglect a kit in pain or danger, even if the kit is from a different Clan.
7. A kit must be at least six moons old to become an apprentice.
8. The deputy will become Clan leader when the leader dies, retires, or is exiled.
9. After the death, retirement, promotion (to a leader status), or exile of the deputy, the new deputy must be chosen before moonhigh.
10. If a Clan member believes that their leader is no longer leading with honor and integrity, they can challenge them. Three-quarters of the Clan members, including their medicine cats, must agree. Their objections will then be presented to the leaders of the other Clans. If the other leaders agree, all medicine cats will request that StarClan remove the leader’s remaining lives and give them to the deputy. These objections cannot be raised by the deputy.
11. A warrior or medicine cat may switch their allegiance from one Clan to another but must meet a set of conditions. The cat wishing to change Clans must perform a task of their intended Clan’s choosing. If they succeed, it will be deemed StarClan’s will that they change Clans, and their request will be granted.
12. Prey is killed only to be eaten. Give thanks to StarClan for its life.
13. Newly appointed warriors will keep a silent vigil for one night after receiving their warrior name.
14. A cat cannot be made deputy without having mentored at least one apprentice.
15. A warrior rejects the soft life of a kittypet.
16. Boundaries must be checked and marked daily. Challenge all trespassing cats — but a Warrior must always remember that all cats follow the warrior code.

The Warrior Cats also have a code for their medicine cats, but there is no written account of them.