A legal malpractice lawsuit is a claim that a lawyer or attorney did not perform to the standard that other reasonable attorneys or lawyers would have in the same situation. The standard of care is described in a number of easy terms including the skill and care with which a case is handled, the judgment of the attorney working the case and the diligence and knowledge of the attorney.
It can be a little hard to prove a case against an attorney, because as long as he or she acted reasonably and within the scope of his or her duties, malpractice isn't likely. However, there are cases where it could be present. For example, an attorney working on the defense and prosecution teams would have conflicting interests in the case and could be held accountable for malpractice.
Or, if you are providing documentation to an attorney and he or she never gets around to reading it, allowing the statute of limitations for your claim to run out purposefully, that attorney could be accused of malpractice. In that case, as an example, you would no longer be able to file your case with the court, making it necessary to seek compensation elsewhere. Your attorney would be the only person you could sue, since he or she hindered your ability to make a claim in a timely manner.
Filing a claim against an attorney can be complicated, which is why working with another firm can be a good option. With the right help, you can define a clear-cut case stating why you feel you've been victimized.
Source: State Bar of Wisconsin, "Legal Malpractice: What Is It, Really?," Jeffrey P. Aiken, accessed Nov. 24, 2016