This chapter provides an in-depth exploration of the different typologies of constitutional facts developed by legal theory, especially in the United States. It argues against distinguishing facts based on the activity performed by the court when it examines them, and against treating social science research as an authoritative source equal to the law. It defends that the kinds of fact must be distinguished according to their content and their relationship with wider litigation: facts are more constitutional (or legislative) the more they transcend the individual case and can be replicated in other suits, and when they concern social or general matters of the world and life in society. In turn, facts are more adjudicative, or case-specific, when they do not present these features. This chapter also defends that case-specific facts can become precedent in relevant questions of law, contrary to the prevailing view in most specific-versus-general classifications of facts in adjudication. Finally, it argues that constitutional/legislative facts need to be found in adversarial proceedings with adequate intervention of experts and interested parties for an appropriate exercise of constitutional adjudication and not simply interpreted according to subjective judgments and impressions.