Any person claiming an interest in the property described in the complaint, and claiming that he or she has been, or will be, injured by a defendant’s activity may intervene in the action.
844.18.Intervenors.
Ch. 844: Interference with Interest; Physical Injury · Last amended 1993 · Last verified July 15, 2026
In one sentenceSection 844.18 lets anyone claiming an interest in the property described in the complaint, who claims a defendant’s activity has injured or will injure them, intervene in a chapter 844 action.
Full Text of Section 844.18
Plain-English Summary
Section 844.18 opens the door for other interested people to join a pending chapter 844 case rather than filing a separate lawsuit. Any person claiming an interest in the property described in the complaint, and claiming that a defendant’s activity has injured or will injure that person, may intervene in the action.
This lets the case gather all the people affected by the same physical injury or interference into one proceeding, rather than leaving them to bring separate suits over the same conduct. It complements Section 844.15’s and 844.16’s recognition that a single piece of real property can carry multiple, distinct interests, each potentially entitled to relief.
Frequently Asked Questions
Can I join an existing lawsuit if I have my own interest in the same property being harmed?
Yes. Section 844.18 allows a person claiming an interest in the property described in the complaint, who claims injury from a defendant’s activity, to intervene in the action.
Do I need to show I have already been injured, or is a threat of future injury enough?
A threat of future injury is enough. Section 844.18 covers a person claiming that they have been, or will be, injured by a defendant’s activity.
Does my interest need to be the same as the existing plaintiff’s interest to intervene?
Section 844.18 requires only that you claim an interest in the property described in the complaint; it does not require that interest to match the existing plaintiff’s interest exactly.
Whose activity does the injury need to come from for me to intervene?
A defendant’s activity. Section 844.18 requires the claimed injury to result from a defendant’s activity in the pending action.
Why would someone want to intervene instead of filing a separate lawsuit?
The statute does not explain the reasoning, but intervening under Section 844.18 lets a person with a related interest be heard in the same proceeding already addressing the defendant’s activity, rather than starting a new case.
Amendment History
History: 1973 c. 189; Sup. Ct. Order, 67 Wis. 2d 585, 767 (1975); Stats. 1975 s. 844.18; 1993 a. 486.
Source & verification. Section text and official notes are
reproduced verbatim from the Wisconsin Statutes, published by the
Wisconsin Legislature (Legislative Reference Bureau). Last verified July 15, 2026.
· Official source
Also known as: wisconsin intervene in property injury lawsuitjoining an existing nuisance lawsuit wisconsin844.18 intervenorsmultiple interest holders same lawsuit wisconsin