Legal malpractice is when a lawyer defaults on their obligation to perform their duties with an appropriate level of care.
In order for a lawyer's actions or omissions to qualify as legal malpractice, there must be significant negligence, or an intent to harm or cause damage to a client.
Even though lawyers are the people who are supposed to handle lawsuits, they too can be sued through legal malpractice. There are even legal malpractice lawyers who work on these cases (they are similar to medical malpractice lawyers).
Because lawyers often deal with issues that are extremely important to their clients' lives, malpractice on their part can have a strong impact on their clients. For this reason, large amounts of damages can be awarded if a lawyer is successfully sued for legal malpractice.