An institutional warrantWarrant is backed by the rules of some institution such as statute law or a game. We present a four step procedure to get from the transcript of the law to the warrantWarrant itself. (1) Go from the written transcript to the transcript as understood. (2) Express that understanding as an A or E categorical. (3) Paraphrase or even symbolize the categorical to bring out its logical structure. (4) Transform this statement into a warrantWarrant by dropping the initial quantifier and taking the antecedent of the immediate subformula as the premisePremise of the warrantWarrant and the consequent as the conclusion. According to Searle, one understands the transcript when one knows its meaning, which is determined by rules for the declarative operatorDeclarative operator, here that an authoritative body has made a declarationDeclaration, and the rules for what the utterance counts as. This involves understanding the propositional content of that declarationDeclaration. Understanding propositional content involves understanding the rules for both referring expressions and predicating expressions. For an institutional warrantWarrant to be reliable, it must be true that a body has declared a backing rule, the body has the legitimate authority to declare the rule, and the propositional content of the rule must be properly understood. Furthermore, identifying exceptions identifies rebuttals Rebuttalto the warrantWarrant a rule backs. The reliabilityReliability of a defeasible warrantDefeasible warrantas an inference rule is a function of the plausibilityPlausibility of the rebuttalsRebuttal. Conditions justifying overturning a legal judgment are degrees of a relevant variableRelevant variable. Considering the law of marriage, we may be able to rank the relevant variablesRelevant variable according to the number of marriages invalidated on the grounds of that variable. We can now address the question of comparative argument strength for arguments with legal warrantsWarrant. The strength of an argument with a legal warrantWarrant is the order of the last relevant variableRelevant variable which it survives. The sufficiency of a warrantWarrant to transfer the acceptability of the premisesPremise to the conclusion depends on the plausibilityPlausibility of the values of the relevant variablesRelevant variable at a given level. Suppose no relevant variableRelevant variable generates a counterexample to an institutional warrantWarrant up to some level i. Suppose counterexamples at a higher level are implausible. The warrantWarrant is presumptively reliable. These considerations on legal warrants may be generalized to warrantsWarrant in general backed by institutional rules.