John Steinbeck penned two iconic works in the 1930s that focused upon migrant workers attempting to cope with the Great Depression: Of Mice and Men 1 and The Grapes of Wrath. 2 And while the fact of lawyers migrating between law firms that span multiple states and jurisdictions does not conjure up the same social justice sensitivities, the professional responsibil-ity issues implicated thereby are important and are not easily resolved. As practicing lawyers know, conflicts e-mails are one of the trademarks of modern multijurisdiction legal practice, rivaled in their ubiquity perhaps only by Seamless.com and the devices through which attorneys receive the e-mails. Hidden behind the comforting familiarity—‘‘Please let me know . . .’’ —however, is a nest of conflicting rules and difficult professional responsibility questions. These issues largely flow from the fact that the rules of professional conduct governing lawyer behavior are rules written by lawyers for lawyers, but based upon an earlier, simpler era. As the business world became increasingly complex, practices grew from single-lawyer, to dozens of lawyers, to (at the extreme end) thousands of lawyers; and potential professional responsibility issues thus not only multiplied, but also mutated into forms that did not exist before. This is especially true with growth pushing law firms into other states and countries, creating the types of conflicts of law issues that always seem to muddle even the simplest of analyses. Perhaps the best example of these issues, and the one that this article focuses on, comes from New York, one of the world’s financial centers and hence a hub of international law firms. After many false starts, 3 the American Bar Association’s Model Rules of Professional Conduct (the ‘‘Model Rules’’) were amended to authorize, in some instances, the use of screening in order to address conflicts issues arising from a lawyer’s prior association with another firm. 4 But the Model Rules are aspirational in nature only; states may (or may not) adopt them in whole or in part. Adopted in 2009, New York’s Rules of Professional Conduct (the ‘‘New York Rules’’), in fact, do not permit screening to address conflicts arising from an attorney’s work at her prior firm, 5 reserving screening as a remedy for more atypical situations like former government employees and judges. 6 One can of course make policy judgments about the wisdom of this approach, 7 but the more pertinent question for practitioners in multijurisdiction law firms is what this means for them and how they should orient their practice. We intend to address this question in two ways. First, we provide a more in-depth summary of the underlying issue. Then, we provide some brief guidance on what practitioners might consider doing in light of this uncertainty. Understanding the Problem Applying conflict rules to law firms begins with the fact that, for the most part, neither the Model Rules nor New York’s Rules directly regulate law ﬁrms’ conflicts, 8 instead largely proscribing the conduct of individual lawyers. 9 Thus, New York’s Rules provide that a lawyer but with the whole firm. Indeed, an engagement letter is usually signed with a firm, and large law firms often tout the diversity of their capabilities in addition to the strength of individual attorneys. In the conflicts realm this issue is dealt with through Rule 1.10(a), the beginning of which is the same in both the Model Rules and the New York Rules: ‘‘While lawyers are associated in a firm, none of them shall knowingly represent a client when any one of them practicing alone would be prohibited from doing so by Rule 1.7, 1.8 or 1.9.’’ 11 On the surface, this squares the circle: a lawyer cannot take on a matter unless all of her colleagues can take on the matter. Clients thus have the allegiance of the entire law firm, not a single attorney. This also preserves confidential information in an era where everything sits in clouds, since, at least in theory, everyone is playing on the same team. Like many solutions, however, this one encounters problems in the execution; when two attorneys are bound by different ethics rules, what rules apply? Or, to offer a more concrete example, imagine a New York attorney at the firm of Ruth & Torre LLP. Having had a streak of losses with their current counsel, the Yankees want to hire the New York Ruth & Torre attorney to represent them in the ongoing matter of Yankees v. Red Sox. The only hiccup is that Ruth & Torre just hired a lateral associate in their Boston office who previously worked on the matter for the Red Sox, doing low value tasks like document review. If only New York law applied, the rules would seem to be clear. 12 The Boston associate would seemingly be prohibited from representing the Yankees absent consent. 13 And the New York attorney, in turn, could not represent anyone that the Boston associate cannot represent, so Ruth & Torre is barred from working on the matter. 14 Under Massachusetts law, however, the issue would not necessarily be this stark; effective screening could be used, even without consent. 15 But which rule applies? New York law simply instructs that an attorney cannot take on another matter that another lawyer in the firm would be prohibited from taking on under New York’s rules. But the Boston associate is not bound by New York rules. This is the type of matter that conflicts of law rules are supposed to address, but unfortunately those do not really solve the issue. In the case of a litigation, New York law says that New York law governs. 16 But it is unclear if this means that New York law can reach out and apply to a lawyer who had minimal contact with the state. 17 And for a nonlitigation matter the issue would only be more confused. 18 Potential Solutions Given this reality, what is a law firm supposed to do, other than hope for change? 19 is limited in her dealings with a client. 10 When a client deals with a large law firm, however, the client does not understand herself to be dealing with just one lawyerOne solution, of course, would be to just turn down the Yankees assignment. But, that raises at least three problems. First, you might not be able to afford that house in the Hamptons you have had your eye on. Second, it places a burden on large law firms, requiring that all attorneys follow the rules in the most restrictive jurisdiction. This is essentially a tax on multijurisdiction law firms, favoring law firms that stay in jurisdictions that allow screening, and thus inhibiting the development of large firms that may benefit clients. At the same time, this rule severely limits the mobility of lawyers. In our example, if it hadn’t been for the Boston associate, the firm of Ruth & Torre would have been able to take on a high profile (and presumably lucrative) matter. In an age of attorney layoffs and decreased vertical prospects for new attorneys, professional responsibility limits on the mobility of associates (let alone partners) are worrisome. Alternatively, a law firm could take a more aggressive approach toward the issue. 20 Aside from just a nonrecommended ‘‘devil may care’’ attitude toward conflicts, New York case law on conflicts of interest is not necessarily as stark as the New York Rules would suggest. In Kassis v. Teacher’s Ins. & Annuity Ass’n, 21 the New York Court of Appeals provided limited support for screening, concluding that ‘‘where one attorney is disqualified as a result of having acquired confidential client information at a former law firm, the presumption that the entirety of the attorney’s current firm must be disqualified may be rebutted.’’ 22 According to the Kassis court, rebutting a presumption of disqualification requires (1) that ‘‘the party seeking to avoid disqualification must prove that any information acquired by the disqualified lawyer is unlikely to be significant or material in the litigation’’ 23 and (2) that the firm have adopted ‘‘adequate screening measures to separate the disqualified lawyer and eliminate any involvement by that lawyer in the representation.’’ 24 It should be noted that the first part of this test is fact intensive. Indeed, the migratory attorney in Kassis was too involved for his new firm to successfully rebut the presumption. 25 It is also important to remember that Kassis only addresses disqualification; and it was decided under New York’s previous ethics code, so its continued validity is not free from doubt. Courts have, however, applied Kassis in the recent past. 26 In addition, this type of situation reinforces the general wisdom of using advance waivers. The comments to the New York Rules provide limited support for such waivers, requiring that the completeness of the disclosure, the extent of the client’s understanding of the risks involved, and the procedures contemplated by the waiver all be assessed. 27 And while such advance waivers initially received a mixed reception, of late they have enjoyed more success in court. 28 To be sure, in the migratory attorney situation such waivers are of limited utility since an attorney’s new firm will not be a signatory to the old firm’s engagement letter. Such provisions can help, however, if the conflict involves two current clients. This is a particular problem for international law firms, since the conflicts rules in foreign jurisdictions can be very different from American rules. For example, one recent case centered around imputing a Hong Kong based representation onto United States litigators despite the fact that, at least according to the respondents on the issue, Hong Kong law would not have prohibited the adverse representation. An advance waiver (albeit in an unsigned engagement letter) prevented the court from having to delve into this thicket of competing regulatory schemes. 29 Closing Thoughts Large multistate law firms are certainly here to stay. And so, at least for the foreseeable future, are interstate differences in legal ethics rules. With states increasingly concerned about migrating lawyers engaging in improper conduct (and tripping over each other in enforcement thereof), 30 the order of the day is caution: law firms need to stop, wait, and carefully analyze each new multijurisdictional matter, as well as each new multijurisdictional hire.