Making one move too many can color your otherwise stellar standing so much that your resume is passed upon simply for evidencing this kind of a history. Law firms might question your acceptance of and ability to thrive in a law firm, or even your long-term commitment to the practice of law itself. Additionally, numerous moves can prompt firms to question your work and whether it was your own weaknesses that forced you to change firms.
In addition to the number of lateral moves you make, you should also consider how your reasons for moving will be perceived by a target employer. As a legal recruiter, often the first question I answer on behalf of my candidates is why they want to move, and I need to be able to provide an acceptable reason to the firm. So if you're considering making a lateral move, I urge you to consider the real driving force behind your desire, and how you will explain these reasons to future employers. Here, I name two reasons that are more palatable to firms than others, and the accompanying issues of which to be aware.