Class action
From United States
Procedure and evidence
What it means
A lawsuit brought by one or a few people on behalf of a large group with the same kind of claim, with the result binding all the group's members unless they opt out.
Why it travels badly
Most legal systems limit a judgment to the parties who are before the court. Many have introduced collective actions, but with very different features: who may sue, whether people must opt in or out, and whether damages are available.
How other systems say it
class action (Federal Rule 23)
A representative sues for a class. Members are bound unless they opt out of the class.
Canada and Australia
class proceedings
Similar to the US model, with rules set by provinces in Canada and by the Federal Court Act in Australia.
ação civil pública and ação coletiva
Public bodies and associations can sue for the collective interest in consumer, environmental and similar matters.
Musterfeststellungsklage and Verbandsklage
Qualified associations bring actions that settle common questions, not personal damages claims by a class.
action de groupe
A collective action, brought by approved associations, for certain categories of claims, such as consumer cases.
Tip for translators and students
Do not use 'class action' for civil-law collective actions without a note. Most differ from the US model on who sues and whether money is awarded.
See the Legal Dictionary entry →
Related: Standing (locus standi), Punitive damages, Discovery
Updated October 2026. Spotted a mistake? Tell us.
TheLawToKnow Tools’s glossary is an educational overview of the main differences between legal systems. It is not legal advice.
