Definition
Accessory actions are proceedings that are subordinate or ancillary to a primary action — that is, legal actions that exist in service of, or in connection with, another main proceeding. The term is principally a Scots law concept and does not occupy a prominent place in English or American common law vocabulary.
In Scots civil procedure, an accessory action is one whose purpose or outcome depends on, or is incidental to, the resolution of a principal action. The accessory action cannot stand on its own terms; its character and effect are shaped by what happens in the primary proceeding it accompanies.
Common Confusion
Despite the shared root word, ACCESSORY ACTIONS and the criminal law concept of an ACCESSORY (a party who aids or abets a crime) are unrelated. The confusion is understandable — both terms derive from the same Latin root meaning "that which attaches to another thing" — but they belong to entirely different doctrinal contexts. Accessory actions is a procedural term in civil and Scots law; accessory as a party to a crime is a substantive criminal law concept. Researchers encountering "accessory" in older legal texts should identify the context carefully before assuming either meaning applies.
Why It Matters in Research
The practical significance of this term for most Law Mind corpus researchers is limited but specific. Three research situations call for awareness of it:
First, researchers working with Scots law materials — particularly older Bell's Dictionary citations, institutional writers such as Stair or Erskine, or historical Court of Session records — will encounter this term as a live procedural concept. In that context it signals a structural relationship between proceedings, not merely a descriptive label.
Second, the term appears in Bouvier through a single-line citation to Bell's Dictionary, which signals that even mid-nineteenth-century American legal lexicography treated this as a foreign (Scots) concept rather than domestic doctrine. Researchers should not assume that encountering "accessory actions" in an American source reflects American procedural practice — it likely reflects borrowing or comparative reference.
Third, the conceptual category — proceedings that are subordinate to or dependent upon a principal proceeding — does appear in American and English practice under different names. Ancillary jurisdiction, supplementary proceedings, and incidental relief are the functional equivalents. A researcher who encounters this term and needs to find analogous doctrine in an American or English context should pivot to those terms.
Historical Dictionary Support
Bouvier's coverage of this term is minimal: a single line noting that in Scots law, accessory actions are "those which are in some degree subservient to others," with attribution to Bell's Dictionary. This brevity is itself informative. Bouvier was writing for an American audience and clearly did not regard the concept as requiring elaboration beyond its Scots-law context. The absence of further development in Bouvier, and the absence of the term from Black's, confirms that this concept never migrated into American legal usage as a distinct term of art.
Bell's Dictionary of the Law of Scotland is the primary historical source for this concept. Researchers needing substantive treatment should consult Bell directly. The Scots institutional writers provide the broader procedural framework within which the concept operates.
Jurisdictional Note
This term is specific to Scots law. It has no recognized equivalent in English common law or American civil procedure, where related concepts travel under different names — ancillary proceedings, dependent claims, or incidental jurisdiction.
Encyclopedia Cross-Reference
The Law Mind Criminal Law Encyclopedia — Criminal Law: Parties to a Crime (Principals and Accessories). Note: that entry addresses criminal accessories (parties to offenses), not accessory actions as a procedural concept. Consult it only to understand the distinction between the two uses of "accessory," not for substantive coverage of this procedural term.