ON PETITION FOR REHEARING
STRUTZ, Judge.The respondent has filed a petition for rehearing in which he strenuously asserts that the opinion of the court in this case *905is basically erroneous for two reasons: (1) that we should have limited our scope of review on the appeal and should not have granted the appellant a trial anew in this court because, he asserts, a trial de novo was not properly demanded; and (2) that the appellant should be estopped from asserting its claim because it had knowledge of Knauss’s action to cancel the Burke contract for deed and did nothing to attempt to intervene in that action, which it could have done to protect its rights. We shall discuss these issues in the order in which they are raised.
On the issue of trial de novo, the respondent asserts that such trial anew was not properly demanded in this case because the appellant did not file a statement of the case in which it made demand for trial de novo. Sec. 28-27-32, N.D.C.C. Because of its failure to file such statement, the respondent argues, a trial de no-vo has not been properly demanded, and this court may not try the case anew on appeal, citing Anderson v. Blixt, 72 N.W.2d 799 (N.D.1955); and Retterath v. Retterath, 76 N.D. 583, 38 N.W.2d 409 (N.D.1949).
The appellant’s demand for trial de novo was made in its notice of appeal. If that were all that had been done, the respondent would be correct in his assertion that this court could not try the case anew. However, the demand for trial de novo was also contained in the settled statement of the case as certified by the trial court. We have held that in any case where a party is entitled to a trial de novo by making proper demand therefor, and the demand for trial de novo is contained in and is a part of the settled statement of the case as certified by the district judge, this court will retry the entire case on appeal. Renner v. Murray, 136 N.W.2d 794 (N.D.1965); Heggen v. Marentette, 144 N.W.2d 218 (N.D.1966).
When our examination of the record in this case disclosed that the settled statement of the case, as certified by the district court, contained the demand for trial de novo, this court proceeded to retry the entire case on appeal. We believe that under the law and the prior decisions of this court, this action was entirely proper.
The second issue raised by the petition for rehearing is that the appellant should be estopped from asserting that it had not been served in the action by Knauss to cancel Burke’s contract for deed, because the appellant had actual knowledge of Knauss’s action against Burke and it did not attempt to intervene and take such steps as would be necessary to protect its interests. Surely, says the respondent, the courts should not reward the appellant for sleeping on its rights, to the detriment of the respondent.
Unless clearly warranted by the facts of the case, estoppel is not favored. Newman v. Albert, 170 Cal.App.2d 678, 339 P.2d 588 (1959). To warrant the application of the doctrine of estoppel, the matter must have a strong appeal to the court’s sense of justice. This court has held that estoppel arises where, by the conduct or acts of another, a party has been induced to alter his position or to do something, to his prejudice, which he otherwise would not have done. Sailer v. Mercer County, 75 N.D. 123, 26 N.W.2d 137 (1947); Woodside v. Lee, 81 N.W.2d 745 (N.D.1957); Grand Forks County v. City of Grand Forks, 123 N.W.2d 42 (N.D.1963); Conklin v. North American Life & Casualty Co., 88 N.W.2d 825 (N.D.1958).
One cannot successfully plead estoppel in the absence of reliance upon acts claimed to operate as an estoppel which changed the position of the one claiming estoppel, to his prejudice. Kennedy v. Lynch Timber Co., 227 Mich. 269, 198 N.W. 985 (1924). Estoppel always is based on the fault of the party estopped. Conner v. Caldwell, 208 Minn. 502, 294 N.W. 650 (1940). Therefore, estoppel will not be applied by the courts unless the one against whom estoppel is asserted has, by *906his acts, conduct, words, or by his silence when he ought to have spoken, misled another to act, to his detriment. In other words, the one who urges estoppel must show that he has been misled or placed in a worse position by the conduct of the one against whom he pleads estoppel. Where it is shown that he has been induced by the conduct of another to change his position, to his injury or disadvantage, the party whose conduct caused such change in position will be estopped from taking advantage thereof.
Let us now look at the record in this case and see whether the doctrine of estoppel should be applied. How has the position of Knauss changed, to his damage or disadvantage, by the failure of Miles to seek intervention in the suit brought by Knauss to cancel Burke’s contract for deed? What did Miles do or refrain from doing which caused Knauss’s position or his rights to be changed, to his damage or injury? Knauss evidently had decided that Burke never would pay the contract for deed, and that he should assert his legal rights and cancel the contract as to him. Knauss’s failure to join Miles in his action resulted in the termination of Burke’s rights only. Miles’s failure to intervene, even if it did know of the action, as asserted by Knauss, did not injure Knauss’s position or impair his rights in the least. Therefore, estoppel may not be asserted against Miles because Knauss has not shown how the failure of Miles to intervene altered his position, to his prejudice. Under the decision of this court, Knauss will receive every cent he has coming for his land, with interest and costs. On the other hand, if this court should rule for the respondent and find that Miles is estopped from asserting its rights because it failed to intervene in the action brought by Knauss to cancel Burke’s contract, as urged by the respondent, then Miles would suffer the loss of its $10,000 building and Knauss would be enriched by that amount.
The respondent has not shown facts which would justify this court in finding that Miles should be estopped from asserting its claim.
For reasons stated, we adhere to our former opinion. The petition for rehearing is denied.
ERICKSTAD, PAULSON and KNUD-SON, JJ., concur.