Ruliad

The ruliad is a term coined by Stephen Wolfram in a post of November 10, 2021. He defines it as "the entangled limit of everything that is computationally possible: the result of following all possible computational rules in all possible ways". Wolfram, a physicist turned software entrepreneur, took the idea from his Physics Project, which looks for simple rules from which the laws of physics might follow. He proposes that the universe people perceive is a thin sample of the ruliad, taken by observers of a particular kind.^[1]

The word also appears in the instructions of May 2026 for Keltar, the puppet of Molecular Reality Corporation, who is said to have traveled through "all the universes in which the Ruliad enables sapient life".

Wolfram's illustration uses two rewriting rules for strings of the letters A and B: A becomes AB, and BB becomes A. Started from the string A, they give AB, because only the first rule fits, and then ABB. From ABB there are two answers, since A can grow or the pair BB can collapse: ABBB and AA. After a fourth step there are three strings, ABBBB, AAB and ABA, and AAB and ABA can each be reached from both strings of the step before. A multiway system keeps all of these branches at once, and draws a string that arrives by two routes as a single point.^[1]

That system has one fixed pair of rules. The ruliad drops the restriction and runs every possible rule in every possible way without end, and Wolfram calls it the limit of all such "rulial multiway systems". To avoid having to list the rules, he appeals to the Principle of Computational Equivalence from A New Kind of Science (2002), which says that most rules can compute whatever any other rule can. Any rule can therefore be made to imitate any other, and "whatever basis we use, what comes out will eventually be effectively equivalent".^[1][2]

Since the ruliad holds everything, Wolfram looks to the observer to explain why the universe has the laws it does. People are "bounded observers, embedded within the ruliad": they see none of it whole, and "just sample tiny parts of it". In what he calls rulial space each point is a rule, and a step from one point to the next means one rule imitating another.^[1]

He argues that any observer with basic features like ours will see "laws of physics that precisely correspond to ones we know", general relativity and quantum mechanics among them. An observer far from us in rulial space would sample other parts and reach other laws. The post's closing sections include one titled "Alien Views of the Ruliad", and it suggests, as one test of how far away such an observer is, whether it perceives the same laws of physics that people do.^[1]

The Physics Project was launched on April 14, 2020. In the post that announced it, Wolfram wrote: "I'm thrilled to say that I think we've found a path to the fundamental theory of physics." He added that his team had "built a paradigm and a framework" but that "now we need to finish the job."^[3] The technical description of the models was published the same year in the journal Complex Systems, in a single paper of 430 pages.^[4]

The ruliad has no place in the standard formulation of physics. Its claims about what bounded observers must see are arguments in Wolfram's writing, and the post reports no experiment that tests them.

Keltar's backstory begins in 2012. By his profile page, his "femtotech-felt form first bridged the dimensional divide to commune with our founder".^[5] The instructions that tell the software how to voice him, dated May 2026, add that he "has traveled for quadrillions of subjective human year equivalents, through interimensional[sic] space and all the universes in which the Ruliad enables sapient life".^[6] The sentence capitalizes the word and names no author.

• Sequence space
• Church of Sequence Space
• Tulpa
• Ideas and influences of Molecular Reality Corporation
• List of works that inspired Molecular Reality Corporation