/s/ ELLISLANDAU

EXHIBIT 10.27

September 18, 2002

Mr. John T. Redmond

President and CEO

MGM Grand Resorts

3799 Las Vegas Boulevard, South

Las Vegas, NV 80109

Dear Mr. Redmond:

This letter agreement (“Letter Agreement”) represents the agreement to an increase in the scope of the Facility (as detailed below), to be constructed in accordance with the terms of that certain Operating Agreement (the “Operating Agreement”) of Marina District Development Holding Co., LLC, a New Jersey limited liability company (“Holding Co.”) as adopted and amended by that certain Contribution and Adoption Agreement, effective December 13, 2000, by and among Holding Co., MAC, CORP., a New Jersey corporation (“MR Sub”) and Boyd Atlantic City, Inc., a New Jersey corporation (“Boyd Sub”). MR Sub and Boyd Sub are the Members of Holding Co. Unless otherwise defined herein, all capitalized terms in this Letter Agreement shall have the same meaning ascribed to such terms in the Operating Agreement.

The parties hereby agree as follows:

A.    MR Sub and Boyd Sub agree and acknowledge that the following shall represent an increase in the scope of the Facility for purposes of Section 3.3(b) (iii) of the Operating Agreement:

Ticket In / Ticket Out Slot Ticketing System

A ticket in / ticket out slot ticketing and redemption system that would include the software and hardware to operate the system, along with all required and necessary equipment to count and redeem ticket in / ticket out vouchers in the cashiering and / or countrooms areas. Such costs shall increase the aggregate shared Project Costs by no more than Seven Million Four Hundred Thousand Dollars ($7,400,000), as described on Exhibit A attached hereto and incorporated herein by this reference.

B.    MR Sub and Boyd Sub shall share equally in the increase, if any, in the aggregate Project Costs up to but not exceeding the approved increase in scope as set forth in Section A of this Letter Agreement. As a result of the approved increase in scope of the Facility, the responsibility of Boyd Sub to make additional capital contributions due to cost overruns, pursuant to Section 3.3(b) of the Operating Agreement, shall not be triggered until, and only to the extent that, the aggregate Project Costs exceed One Billion Sixty Two Million Five Hundred Thousand Dollars ($1,062,500,000), which represents One Billion Thirty Five Million Dollars ($1,035,000,000) plus the amount set forth Section A of this Letter Agreement, plus the Increase in Scope of Construction of the Borgata Agreement Letter dated January 16, 2002 between Boyd Atlantic City, Inc. and MAC Corp. Correspondingly, Boyd Sub and MR Sub shall

Mr. John T. Redmond

September 18, 2002

Page Two

share equally in all In Balance Contributions, if any, required by the provider of Construction Financing to the extent such In Balance Contributions relate to the approved increase in scope as set forth in this Letter Agreement.

C.    The Ticket in / Ticket out system and all related equipment and components shall be considered a part of the Program and the Facility for all purposes under the Operating Agreement.

Please indicate your agreement to the terms of this Letter Agreement by countersigning below, where indicated.

ACCEPTED AND AGREED TO this 1st day of October, 2002: