A rudimentary version of the phrase was first used by members of Artabanus' group, a precursor to the Brotherhood.

' Nothing is true everything is permitted' was the Creed's maxim and primary guideline. It commands us to be wise.' ―Altaïr Ibn-La'Ahad. 'Our Creed does not command us to be free. This was reflected on by Altaïr Ibn-La'Ahad when about to kill a target who was ordering a mass burning of books. Rather, they demonstrated the way in which they embraced contradiction, 'that one may be two things – opposite in every way – simultaneously.' Another core part of the Creed is the importance of knowledge, which allows one to learn and advance. Though seemingly hypocritical, the ironies did not undermine the Assassins' cause.

The Assassins seek to reveal the danger of blind faith, yet practice it themselves.

The Assassins seek to open the minds of men, but require obedience to rules.

The Assassins seek to promote peace, but commit murder.

The three great ironies were observations that had been noted as early as the Roman Empire, and described the contradictions between the Creed and the actions of the Assassins who followed it.

'Do we bend the rules in service to a greater good? And if we do, what does it say of us?' ―Altaïr's Codex, page 4. He went on to explain that the Creed was an idea, and even if all records of it were destroyed, it could eventually be reinvented by another. In the Altaïr Ibn-La'Ahad's Codex, it was stated that the Creed cannot be killed, even if all of its followers were. Al Mualim, one of the Mentors of the Order, once remarked that ' are nothing if do not abide by the Assassin's Creed'. After generations of the Assassins handing the Creed down orally to ensure that its message was delivered to and upheld by every member, they settled on their three tenets sometime in the 9th century.

The Creed began to take shape in 38 BCE when the Medjay Bayek of Siwa and Aya of Alexandria founded the Hidden Ones. It restricted unnecessary slaughter of innocents, preserved the reputation of oneself and of the Order, and was meant to create peace not only within the world, but within the individual. The Assassin's Creed, often referred to as the Creed, was a code and guiding philosophy of the Assassin Order upheld from the High Middle Ages until the modern era. 'Nothing is true, everything is permitted.' ―The Creed's maxim.

Assassin's creed identity