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                                                                     EXHIBIT 5.1

                        [MORRISON & FOERSTER LETTERHEAD]

                                September 17, 1997


Boyd Gaming Corporation
2950 South Industrial Road
Las Vegas, Nevada  89109

        Re:  9.50% Senior Subordinated Notes Due 2007;
             Registration Statement on Form S-4

Ladies and Gentlemen:

        We have acted as counsel for Boyd Gaming Corporation, a Nevada
corporation (the "Company"), in connection with the Registration Statement (the
"Registration Statement") on Form S-4 under the Securities Act of 1933, as
amended, for the registration and sale of an aggregate of $250,000,000 principal
amount of 9.50% Senior Subordinated Notes Due 2007 (the "Notes") by the Company,
in connection with the exchange offer (the "Exchange Offer") of $250,000,000 in
previously issued 9.50% Senior Subordinated Notes Due 2007 (the "Old Notes") for
the Notes. The Old Notes have been and the Notes will be issued pursuant to the
terms and conditions of, and in the forms set forth in, an indenture (the
"Indenture") between the Company and State Street Bank and Trust Company, a
Massachusetts banking corporation, as trustee (the "Trustee"), the form of which
is filed as an exhibit to the Registration Statement.

        We have examined originals or copies of the Indenture and the Notes. In
addition, we have examined such records, documents, certificates of public
officials and of the Company, made such inquiries of officials of the Company,
and considered such questions of law as we have deemed necessary for the purpose
of rendering the opinions set forth herein.

        We have assumed the genuineness of all signatures, the authenticity of
all Notes submitted to us as originals and the conformity with originals of all
items submitted to us as copies. We have also assumed that each party to the
Indenture and the Notes, other than the Company, has the power and authority to
execute and deliver, and to perform and observe the provisions of, the Indenture
and the Notes, and has duly authorized, executed and delivered the Indenture and
the Notes, that the Indenture constitutes the legal, valid and binding
obligations of the Trustee, and that the Indenture has been duly authenticated
by the Trustee and will be duly qualified under the Trust 


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Boyd Gaming Corporation
September 17, 1997
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Indenture Act of 1939, as amended. We have also assumed compliance with all
applicable state securities and "Blue Sky" laws.

        The opinions hereinafter expressed are subject to the following further
qualifications and exceptions:

        (i) The effect of bankruptcy, insolvency, reorganization, arrangement,
moratorium or other similar laws relating to or affecting the rights of
creditors generally, including, without limitation, laws relating to fraudulent
transfers or conveyances, preferences and equitable subordination;

        (ii) Limitations imposed by general principles of equity upon the
availability of equitable remedies or the enforcement of provisions of the Notes
and the Indenture; and the effect of judicial decisions which have held that
certain provisions are unenforceable where their enforcement would violate the
implied covenants of good faith and fair dealing, or would be commercially
unreasonable, or where their breach is not material;

        (iii) We express no opinion as to the effect on the opinions expressed
herein of (a) the compliance or non-compliance of any party to the Indenture or
the Notes (other than the Company) with any laws or regulations applicable to
it, or (b) the legal or regulatory status or the nature of the business of any
such party;

        (iv) The effect of judicial decisions which may permit the introduction
of extrinsic evidence to supplement the terms of the Indenture or the Notes or
to aid in the interpretation of the Indenture or the Notes;

        (v) We express no opinion as to the enforceability of provisions of the
Indenture or the Notes imposing, or which are construed as effectively imposing,
penalties;

        (vi) The enforceability of provisions of the Indenture or the Notes
which purport to establish evidentiary standards or to make determinations
conclusive; and

        (vii) We express no opinion as to the enforceability of any choice of
law provisions contained in the Indenture or the Notes or the enforceability of
any provisions which purport to establish a particular court as the forum for
adjudication of any controversy relating to the Indenture or the Notes or which
purport to cause any party to waive or alter any right to a trial by jury or
which waive objection to jurisdiction.



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Boyd Gaming Corporation
September 17, 1997
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        Based upon and subject to the foregoing, we are of the opinion that:

        1. The Notes, upon valid tender of the Old Notes to State Street Bank
and Trust Company, as exchange agent for the Exchange Offer, and issuance of the
Notes in exchange for such tendered Old Notes in accordance with the terms of
the Registration Statement, will be legally issued and will constitute binding
obligations of the Company.

        We express no opinion as to matters governed by laws of any jurisdiction
other than the following as in effect on the date hereof: the substantive laws
of the State of New York (without reference to its choice of law rules), the
general corporation laws of the State of Nevada (in sole reliance upon the
opinion of McDonald Carano Wilson McCune Bergin Frankovich & Hicks LLP), and the
federal laws of the United States of America.

        We hereby consent to the use of this opinion in connection with the
Registration Statement and to the reference to our firm under the caption "Legal
Matters" therein.

                                    Very truly yours,

                                    /s/ Morrison & Forester LLP