Opinion by
Smith, J.,
This is an action by an attorney-at-law against his client, to recover compensation for professional services. The defense is that there was such negligence in the performance of the services that the client suffered serious loss, and that for this reason the plaintiff has no just claim to compensation.
An attorney is not liable to his client for a failure to succeed, resulting in loss to the client, unless this is due to his mismanagement of the business intrusted to him, through bad faith, inattention or want of professional skill. Without discussing at length the degree of skill and care required of an attorney, it is sufficient for the purposes of the case in hand to say that he must, at least, be familiar with the well-settled principles of law and rules of practice which are of frequent application in the ordinary business of the profession; must observe the utmost good faith toward his client;; and must give such attention to his duties, and to the interests of his client, as ordinary prudence demands, or members of the profession usually bestow. For loss to his client, resulting from the lack of this measure of professional duty and attainments, he must be held liable; and such loss forms an equitable defense to his demand for compensation.
Tested by this standard, there was an obvious lack of pro*468fessional skill and’ care on the part of the defendant, in the proceedings for the collection of the Wolfgang claims. An attorney must be held to know the return day of process issued by his direction, must keep himselfinfonqed of the steps taken by the sheriff in its execution, and must give all instructions necessary to secure his client’s interests. It is usual for the attorney, on execution process, to give directions respecting the property which he desires should be sold, especially when this is real estate; and, if he omits this, he should, at least, ascertain what has been done in the premises by the sheriff and act as the interest of his client requires. He must be held to know that when the' return day of a fi. fa. has passed without a levy, the writ is functus officio; that a vend. ex. is issued only for a sale by virtue of a levy made on an antecedent writ; and he must at all times inform himself of the state of the record, and of the sheriff’s proceedings, before taking or directing any further step based thereon. Here the fi. fa. was issued June 25, 1897, returnable July 5. It remained without action by the sheriff until July 8, when a levy was made on the defendant’s real and personal property. The latter was sold August 10, and between that date and August 19 the writ was returned with the real estate levy. On August 20 a vend. ex. was issued, by the plaintiff’s direction, for the sale of the land described in the levy. Later, the fi. fa. was taken from the prothonotary’s office, and on August 25 an inquisition was held under the act of 1840, with six jurors, to ascertain whether that portion of the land lying in Schuylkill county could be sold separately, with a finding against such sale. The fi. fa., with the inquisition attached, was then returned to the prothonotary’s office, and September 11 the laird was sold on the vend. ex. to- the judgment creditor for 18,500.
The proceedings subsequent to the return day of the fi. fa. were wholly irregular, and no title passed by the sale. They were in disregard of well-settled rules of practice, which every attorney must be expected to understand and observe. An attorney is not, indeed, responsible for a mistake of the sheriff to which he in no way contributes. But when he acquiesces in such a mistake, and directs further proceedings, founded on it, he makes the error his own, and is answerable for the loss *469to his client arising from snch proceedings. Here the only mistake made by the sheriff, independently of the plaintiff, was in making a levy after the return day of the fi. fa., when-the writ no longer authorized it. This, of itself, was a harmless matter, and would have resulted in no, ill consequences had not the plaintiff adopted it as a valid levy, and made it the foundation of the inquisition and sale. In these proceedings the sheriff and his deputy acted in accordance with the plaintiff’s instructions, apparently against the depiity’s better judgment, and after he had suggested the propriety of staying the vend. ex. and issuing an alias fi. fa. on which to hold the inquisition. Instead of acting on this suggestion, the plaintiff chose to proceed on the erroneous levy, and fixed the number of jurors for the inquisition at six. We do riot say, however, that the proper number of jurors was a matter admitting of no doubt, or that an error on this point should be deemed professional negligence. Neither the act of 1836, requiring an inquisition of rents and profits for seven years, nor the act of 1840, requiring an inquisition of lands lying in adjoining counties, specifies the number of jurors; the provision of each being that the sheriff shall “ summon an inquest.” As to the former inquisition, the Act of January 12, 1705, 1 Sm. L. 57, fixed the number at twelve, and the Act of March 21, 1806, 4 Sm. L. 326, provided that on a levy of real estate “ such proceedings shall be had as the existing laws direct.” The practice under the act of 1836 necessarily followed the act of 1705 as to the number of jurors, and in default of an}*- other, pro vision this was adopted in proceedings under the act of 1840. The Acts of June 11, 1879, P. L. 122, and May 10, 1881, P. L. 13, fixed the number of -jurors in an inquisition of rents and profits at six, and the former repealed all'-inconsistent acts and parts of acts. This repealed the act of 1705 as to the number of jurors. Whether, on this point, in proceedings under the act of 1840, the act of 1705 is to be deemed still subsisting, or the inquest should be in conformity with the acts of 1879 and 1881, we need not here decide. The question is not so free from doubt that an attorney must be required to decide it correctly, on pain of being held lacking in professional knowledge should the courts reach a different conclusion. But the fatal defect in the proceeding was in .holding an inquisition on *470a writ after its authority was exhausted, with a sale on a writ not warranted by the state of the record. There being no valid levy, there was no authority for inquisition or sale; and this was so obvious that it should have been detected by the exercise of ordinary care on the part of an attorney.
The contention that the defendant, by his continued employment of the plaintiff after the inquisition and sale, ratified his acts, cannot be sustained. Through lack of professional knowledge, the defendant was unable to judge of the situation, and trusted to the plaintiff for information; while it was not until October 11, 1901, that it was judicially determined, in Boyer v. Miller, 200 Pa. 589, that he acquired no title to the land. Meantime the plaintiff, orally and in correspondence, steadily insisted that the proceedings were regular. After assuring him for years that his title was good, it comes with an ill grace for the attorney now to contend that his client should have known that the law was otherwise, and ceased to employ him. When the condition of the title became manifest, the further employment of the plaintiff appears to have been chiefly in negotiations designed to minimize the loss; but while the plaintiff evidently secured the best result attainable, his employment for the purpose committed the defendant to nothing by way of ratification of the acts to which the loss was due.
The plaintiff further contends that as the plea of set-off was not entered until more than six years after the inquisition and sale, the statute of limitations is a bar to any claim on the part of the defendant growing out of the alleged negligence. This view rests on a misconception. When an action is based on the defendant’s negligence, the statute of limitations operates on it as on any other. And when a demand, arising from the plaintiff’s negligence in an independent transaction, is set up by the defendant as a counter claim, under our defalcation act, this is, in like manner, subject to the bar of the statute. But negligence on the part of the plaintiff, inherent in the cause of action, and operating to defeat it, stands oh different ground. In an action on a contract, the right of recovery is based on performance; hence, whether due to negligence or to other causes, nonperformance is a full defense, and ill performance a defense pro tanto. Such defense is not merely a set-off, balancing or reducing the plaintiff’s demand, but strikes at his *471right of action by impeaching the consideration on which it rests, and showing that, ex aequo et bono, his claim has no foundation, or is limited in measure. It requires no special plea, but may be shown under the general issue, and is so involved in the cause of action that it cannot be separated, and subjected independently to the operation of the statute of limitations. As long as an action on the contract is not barred by the statute, failure of performance from any cause, as a defense in whole or in part, remains unaffected by it.
Notwithstanding the able argument in behalf of the appellant, and a careful examination of the charge and evidence, we are unable to find any ground on "which the specifications of error can be sustained. In ruling on questions of evidence, and in the charge and answers to points, the trial judge was considerate of the plaintiff’s position, professionally, and carefully guarded his rights in the premises. The matters in controversy were submitted to the jury with instructions that gave the plaintiff at least every advantage to which .he was entitled, and there appears no reason for regarding the verdict as unwarranted by the evidence.
Judgment affirmed.