<PAGE>

                                    GUARANTY
                                    --------


          This GUARANTY ("Guaranty"), dated as of March 18, 1999, is made by
Coast Resorts, Inc., a Nevada corporation ("Guarantor") in favor of Bank of
America National Trust and Savings Association, as Administrative Agent for the
benefit of the Lenders that are party to the Loan Agreement referred to below
(collectively with the Lenders, "Lender"), with reference to the following
facts:

                                    RECITALS
                                    --------

          A.   Pursuant to the Loan Agreement dated as of March 18, 1999 by and
among Coast Hotels and Casinos, Inc., a Nevada corporation (the "Borrower"), the
lenders from time to time party thereto (collectively, the "Lenders" and
individually, a "Lender"), and Bank of America National Trust and Savings
Association, as Administrative Agent (as such agreement may from time to time be
extended, modified, renewed, restated, supplemented or amended, the "Loan
Agreement"), the Lenders are making certain credit facilities available to
Borrower.

          B.   As a condition to the availability of such credit facilities,
Guarantor is required to enter into this Guaranty and to guaranty the Guarantied
Obligations as hereinafter provided.

          C.   Guarantor expects to realize direct and indirect benefits as the
result of the availability of the aforementioned credit facilities to Borrower.

                                   AGREEMENT
                                   ---------

          NOW, THEREFORE, in order to induce Lender to continue to extend the
aforementioned credit facilities, and for other good and valuable consideration,
the receipt and adequacy of which hereby are acknowledged, Guarantor hereby
represents, warrants, covenants, agrees and guaranties as follows:

          1.   Definitions.  This Guaranty is one of the Guaranties referred to
               -----------
in the Loan Agreement and is one of the Loan Documents.  Terms defined in the
Loan Agreement and not otherwise defined in this Guaranty shall have the
meanings given those terms in the Loan Agreement when used herein and such
definitions are incorporated herein as though set forth in full.  In addition,
as used herein, the following terms shall have the meanings respectively set
forth after each:

          "Guarantied Obligations" means all Obligations of Borrower or any
           ----------------------
          other Obligor at any time and from time to time owed to Lender under
          one or more of the Loan Documents (but not including Obligations

                                      -1-
<PAGE>

          owed to Lender under this Guaranty), whether due or to become due,
          matured or unmatured, liquidated or unliquidated, or contingent or non
          contingent, including obligations of performance as well as
                      ---------
          obligations of payment, and including interest that accrues after the
                                      ---------
          commencement of any bankruptcy or insolvency proceeding by or against
          Guarantor, any other Obligor or any other Person.

          "Guarantor" means Coast Resorts, Inc., a Nevada corporation.
           ---------

          "Guaranty" means this Guaranty, and any extensions, modifications,
           --------
          renewals, restatements, reaffirmations, supplements or amendments
          hereof.

          "Lender" means the Administrative Agent (acting as the Administrative
           ------
          Agent and/or on behalf of the Lenders), and the Lenders, and each of
          them, and any one or more of them.  Subject to the terms of the Loan
          Agreement, any right, remedy, privilege or power of Lender may be
          exercised by the Administrative Agent, or by the Requisite Lenders, or
          by any Lender acting with the consent of the Requisite Lenders.

          2.   Guaranty of Guarantied Obligations.  Guarantor hereby
               ----------------------------------
irrevocably, unconditionally guaranties and promises to pay and perform on
demand the Guarantied Obligations and each and every one of them, including all
                                                                  ---------
amendments, modifications, supplements, renewals or extensions of any of them,
whether such amendments, modifications, supplements, renewals or extensions are
evidenced by new or additional instruments, documents or agreements or change
the rate of interest on any Guarantied Obligation or the security therefor, or
otherwise.

          3.   Nature of Guaranty.  This Guaranty is irrevocable and continuing
               ------------------
in nature and relates to any Guarantied Obligations now existing or hereafter
arising.  This Guaranty is a guaranty of prompt and punctual payment and
performance and is not merely a guaranty of collection.

          4.   Relationship to Other Agreements.  Nothing herein shall in any
               --------------------------------
way modify or limit the effect of terms or conditions set forth in any other
document, instrument or agreement executed by Guarantor or in connection with
the Guarantied Obligations, but each and every term and condition hereof shall
be in addition thereto.  All provisions contained in the Loan Agreement or any
other Loan Document that apply to Loan Documents generally are fully applicable
to this Guaranty and are incorporated herein by this reference.

          5.   Subordination of Indebtedness of Borrower to Guarantor to the
               -------------------------------------------------------------
Guarantied Obligations.  Guarantor agrees that:
----------------------

                                      -2-
<PAGE>

               (a) Any indebtedness of Borrower now or hereafter owed to
     Guarantor hereby is subordinated to the Guarantied Obligations.

               (b) If Lender so requests, upon the occurrence and during the
     continuance of any Event of Default, any such indebtedness of Borrower now
     or hereafter owed to Guarantor shall be collected, enforced and received by
     Guarantor as trustee for Lender and shall be paid over to Lender in kind on
     account of the Guarantied Obligations, but without reducing or affecting in
     any manner the obligations of Guarantor under the other provisions of this
     Guaranty.

               (c) Should Guarantor fail to collect or enforce any such
     indebtedness of Borrower now or hereafter owed to Guarantor and pay the
     proceeds thereof to Lender in accordance with Section 5(b) hereof, Lender
                                                           ----
     as Guarantor's attorney-in-fact may do such acts and sign such documents in
     Guarantor's name as Lender considers necessary or desirable to effect such
     collection, enforcement and/or payment.

          6.   Statutes of Limitations and Other Laws.  Until the Guarantied
               --------------------------------------
Obligations shall have been paid and performed in full, all the rights,
privileges, powers and remedies granted to Lender hereunder shall continue to
exist and may be exercised by Lender at any time and from time to time
irrespective of the fact that any of the Guarantied Obligations may have become
barred by any statute of limitations.  Guarantor expressly waives the benefit of
any and all statutes of limitation, and any and all Laws providing for exemption
of property from execution or for evaluation and appraisal upon foreclosure, to
the maximum extent permitted by applicable Laws.

          7.   Waivers and Consents.  Guarantor acknowledges that the
               --------------------
obligations undertaken herein involve the guaranty of obligations of Persons
other than Guarantor and, in full recognition of that fact, consents and agrees
that Lender may, at any time and from time to time, without notice or demand,
and without affecting the enforceability or continuing effectiveness hereof:
(a) supplement, modify, amend, extend, renew, accelerate or otherwise change the
time for payment or the terms of the Guarantied Obligations or any part thereof,
including any increase or decrease of the rate(s) of interest thereon; (b)
---------
supplement, modify, amend or waive, or enter into or give any agreement,
approval or consent with respect to, the Guarantied Obligations or any part
thereof, or any of the Loan Documents to which Guarantor is not a party or any
additional security or guaranties, or any condition, covenant, default, remedy,
right, representation or term thereof or thereunder; (c) accept new or
additional instruments, documents or agreements in exchange for or relative to
any of the Loan Documents or the Guarantied Obligations or any part thereof; (d)
accept partial payments on the Guarantied Obligations; (e) receive and hold
additional security or guaranties for the Guarantied Obligations or any part
thereof; (f) release, reconvey, terminate, waive, abandon, fail to perfect,
subordinate, exchange, substitute, transfer and/or enforce any security or
guaranties, and apply any security and direct the order or manner of sale
thereof as Lender in

                                      -3-
<PAGE>

its sole and absolute discretion may determine; (g) release any Person from any
personal liability with respect to the Guarantied Obligations or any part
thereof; (h) settle, release on terms satisfactory to Lender or by operation of
applicable Laws or otherwise liquidate or enforce any Guarantied Obligations and
any security or guaranty therefor in any manner, consent to the transfer of any
security and bid and purchase at any sale; and/or (i) consent to the merger,
change or any other restructuring or termination of the corporate existence of
Borrower, Guarantor or any other Person, and correspondingly restructure the
Guarantied Obligations, and any such merger, change, restructuring or
termination shall not affect the liability of Guarantor or the continuing
effectiveness hereof, or the enforceability hereof with respect to all or any
part of the Guarantied Obligations.

          Upon the occurrence and during the continuance of any Event of
Default, Lender may enforce this Guaranty independently as to Guarantor and
independently of any other remedy or security Lender at any time may have or
hold in connection with the Guarantied Obligations.  Guarantor expressly waives
any right to require Lender to marshal assets in favor of Guarantor, and agrees
that Lender may proceed against Borrower, or upon or against any security or
remedy, before proceeding to enforce this Guaranty, in such order as it shall
determine in its sole and absolute discretion.  Lender may file a separate
action or actions against Borrower and/or Guarantor without respect to whether
action is brought or prosecuted with respect to any security or against any
other Person, or whether any other Person is joined in any such action or
actions.  Guarantor agrees that Lender, Borrower and any Affiliates of Borrower
or Borrower may deal with each other in connection with the Guarantied
Obligations or otherwise, or alter any contracts or agreements now or hereafter
existing between any of them, in any manner whatsoever, all without in any way
altering or affecting the security of this Guaranty.  Lender's rights hereunder
shall be reinstated and revived, and the enforceability of this Guaranty shall
continue, with respect to any amount at any time paid on account of the
Guarantied Obligations which thereafter shall be required to be restored or
returned by Lender upon the bankruptcy, insolvency or reorganization of Borrower
or any other Person, or otherwise, all as though such amount had not been paid.
The rights of Lender created or granted herein and the enforceability of this
Guaranty with respect to Guarantor at all times shall remain effective to
guaranty the full amount of all the Guarantied Obligations even though the
Guarantied Obligations, or any part thereof, or any security or guaranty
therefor, may be or hereafter may become invalid or otherwise unenforceable as
against Borrower or any other guarantor or surety and whether or not Borrower
shall have any personal liability with respect thereto.  To the maximum extent
permitted by law, Guarantor expressly waives any and all defenses now or
hereafter arising or asserted by reason of (a) any disability or other defense
of Borrower with respect to the Guarantied Obligations, (b) the unenforceability
or invalidity of any security or guaranty for the Guarantied Obligations or the
lack of perfection or continuing perfection or failure of priority of any
security for the Guarantied Obligations, (c) the cessation for any cause
whatsoever of the liability of Borrower (other than by reason of the full
payment and performance of all Guarantied Obligations), (d) any failure of
Lender to marshal assets in favor of Borrower or any other Person, (e) except as
otherwise provided in this Guaranty, any

                                      -4-
<PAGE>

failure of Lender to give notice of sale or other disposition of Collateral to
Guarantor or any other Person or any defect in any notice that may be given in
connection with any sale or disposition of Collateral, (f) any failure of Lender
to comply with applicable Laws in connection with the sale or other disposition
of any Collateral or other security for any Guarantied Obligation, including
without limitation, any failure of Lender to conduct a commercially reasonable
sale or other disposition of any Collateral or other security for any Guarantied
Obligation, (g) any act or omission of Lender or others that directly or
indirectly results in or aids the discharge or release of Borrower or the
Guarantied Obligations or any security or guaranty therefor by operation of law
or otherwise, (h) any Law which provides that the obligation of a surety or
guarantor must neither be larger in amount nor in other respects more burdensome
than that of the principal or which reduces a surety's or guarantor's obligation
in proportion to the principal obligation, (i) any failure of Lender to file or
enforce a claim in any bankruptcy or other proceeding with respect to any
Person, (j) the election by Lender, in any bankruptcy proceeding of any Person,
of the application or non-application of Section 1111(b)(2) of the United States
Bankruptcy Code, (k) any extension of credit or the grant of any Lien under
Section 364 of the United States Bankruptcy Code, (l) any use of cash collateral
under Section 363 of the United States Bankruptcy Code, (m) any agreement or
stipulation with respect to the provision of adequate protection in any
bankruptcy proceeding of any Person, (n) the avoidance of any Lien in favor of
Lender for any reason, (o) any bankruptcy, insolvency, reorganization,
arrangement, readjustment of debt, liquidation or dissolution proceeding
commenced by or against any Person, including any discharge of, or bar or stay
                                    ---------
against collecting, all or any of the Guarantied Obligations (or any interest
thereon) in or as a result of any such proceeding, (p) to the extent permitted,
the benefits of any form of one-action rule, or (q) any action taken by Lender
that is authorized by this Section or any other provision of any Loan Document.
Guarantor expressly waives all setoffs and counterclaims and all presentments,
demands for payment or performance, notices of nonpayment or nonperformance,
protests, notices of protest, notices of dishonor and all other notices or
demands of any kind or nature whatsoever with respect to the Guarantied
Obligations, and all notices of acceptance of this Guaranty or of the existence,
creation or incurrence of new or additional Guarantied Obligations.

          8.   Condition of Borrower and Borrower's Subsidiaries.  Guarantor
               -------------------------------------------------
represents and warrants to Lender that Guarantor has established adequate means
of obtaining from Borrower and Borrower's Subsidiaries, on a continuing basis,
financial and other information pertaining to the businesses, operations and
condition (financial and otherwise) of Borrower and Borrower's Subsidiaries and
their Properties, and Guarantor now is and hereafter will be completely familiar
with the businesses, operations and condition (financial and otherwise) of
Borrower and Borrower's Subsidiaries and their Properties.  Guarantor hereby
expressly waives and relinquishes any duty on the part of Lender (should any
such duty exist) to disclose to Guarantor any matter, fact or thing related to
the businesses, operations or condition (financial or otherwise) of Borrower or
Borrower's Subsidiaries or their Properties, whether now known or hereafter
known by Lender during the life of this Guaranty.  With respect to any of the
Guarantied Obligations, Lender need not inquire into the

                                      -5-
<PAGE>

powers of Borrower or any Subsidiaries thereof or the officers or employees
acting or purporting to act on their behalf, and all Guarantied Obligations made
or created in good faith reliance upon the professed exercise of such powers
shall be secured hereby.

          9.   Liens on Real Property.  In the event that all or any part of the
               ----------------------
Guarantied Obligations at any time are secured by any one or more deeds of trust
or mortgages or other instruments creating or granting Liens on any interests in
real Property, Guarantor authorizes Lender, upon the occurrence of and during
the continuance of any Event of Default, at its sole option, without notice or
demand and without affecting any Guarantied Obligations of Guarantor, the
enforceability of this Guaranty, or the validity or enforceability of any Liens
of Lender on any Collateral, to foreclose any or all of such deeds of trust or
mortgages or other instruments by judicial or nonjudicial sale.  Guarantor
expressly waives any defenses to the enforcement of this Guaranty or any rights
of Lender created or granted hereby or to the recovery by Lender against
Borrower or any other Person liable therefor of any deficiency after a judicial
or nonjudicial foreclosure or sale because all or any part of the Guarantied
Obligations is secured by real Property.  This means, among other things: (1)
Lender may collect from any Guarantor without first foreclosing on any real or
personal Property collateral pledged by Borrower.  (2) If the Lender forecloses
on any real Property collateral pledged by Borrower: (A) The amount of the
Guarantied Obligations may be reduced only by the price for which that
collateral is sold at the foreclosure sale, even if the collateral is worth more
than the sale price.  (B) The Lender may collect from any Guarantor even if the
Lender, by foreclosing on the real Property collateral, has destroyed any right
any Guarantor may have to collect from Borrower.  This is an unconditional and
irrevocable waiver of any rights and defenses any Guarantor may have because all
or any part of the Guarantied Obligations is secured by real Property. Guarantor
expressly waives any defenses or benefits that may be derived from California
Code of Civil Procedure (S)(S) 580a, 580b, 580d or 726, or comparable provisions
of the Laws of any other jurisdiction, including, without limitation, NRS
Section 40.430 and judicial decisions relating thereto, and NRS Sections 40.451,
40.455, 40.457 and 40.459 and all other suretyship defenses it otherwise might
or would have under California Law or other applicable Law.  Guarantor expressly
waives any right to receive notice of any judicial or nonjudicial foreclosure or
sale of any real Property or interest therein subject to any such deeds of trust
or mortgages or other instruments and any Guarantor's or any other Person's
failure to receive any such notice shall not impair or affect Guarantor's
Obligations or the enforceability of this Guaranty or any rights of Lender
created or granted.

          10.  Waiver of Rights of Subrogation.  Notwithstanding anything to the
               -------------------------------
contrary elsewhere contained herein or in any other Loan Document to which
Guarantor is a Party, unless and until all Obligations have been paid and
performed in full, Guarantor hereby expressly waives with respect to Borrower
and its successors and assigns (including any surety) and any other Person which
                                ---------
is directly or indirectly a creditor of Borrower or any surety for Borrower, any
and all rights at Law or in equity to subrogation, to reimbursement, to
exoneration, to contribution, to setoff or to any other rights that could accrue
to a surety

                                      -6-
<PAGE>

against a principal, to a guarantor against a maker or obligor, to an
accommodation party against the party accommodated, or to a holder or transferee
against a maker, and which Guarantor may have or hereafter acquire against
Borrower or any other such Person in connection with or as a result of
Guarantor's execution, delivery and/or performance of this Guaranty or any other
Loan Document to which Guarantor is a party. Guarantor agrees that it shall not
have or assert any such rights against Borrower or its successors and assigns or
any other Person (including any surety) which is directly or indirectly a
                  ---------
creditor of Borrower or any surety for Borrower, either directly or as an
attempted setoff to any action commenced against Guarantor by Borrower (as
borrower or in any other capacity), Lender or any other such Person unless and
until all Obligations have been paid and performed in full.  Guarantor hereby
acknowledges and agrees that this waiver is intended to benefit Borrower and
Lender and shall not limit or otherwise affect Guarantor's liability hereunder,
under any other Loan Document to which Guarantor is a party, or the
enforceability hereof or thereof.

          11.  Understandings With Respect to Waivers and Consents.  Guarantor
               ---------------------------------------------------
warrants and agrees that each of the waivers and consents set forth herein are
made with full knowledge of their significance and consequences, with the
understanding that events giving rise to any defense or right waived may
diminish, destroy or otherwise adversely affect rights which Guarantor otherwise
may have against Borrower, Lender or others, or against any Collateral, and
that, under the circumstances, the waivers and consents herein given are
reasonable and not contrary to public policy or Law.  Guarantor acknowledges
that it has either consulted with legal counsel regarding the effect of this
Guaranty and the waivers and consents set forth herein, or has made an informed
decision not to do so.  If this Guaranty or any of the waivers or consents
herein are determined to be unenforceable under or in violation of applicable
Law, this Guaranty and such waivers and consents shall be effective to the
maximum extent permitted by Law.

          12.  Representations and Warranties.  Guarantor  hereby makes each and
               ------------------------------
every representation and warranty applicable to Guarantor set forth in Article 4
                                                                       ---------
of the Loan Agreement as if set forth in full herein.

          13.  Costs and Expenses.  Guarantor agrees to pay to Lender all costs
               ------------------
and expenses (including, without limitation, reasonable attorneys' fees and
              ---------
disbursements) incurred by Lender in the enforcement or attempted enforcement of
this Guaranty, whether or not an action is filed in connection therewith, and in
connection with any waiver or amendment of any term or provision hereof.  All
advances, charges, costs and expenses, including reasonable attorneys' fees and
                                       ---------
disbursements (including the reasonably allocated cost of legal counsel employed
by Lender), incurred or paid by Lender in exercising any right, privilege, power
or remedy conferred by this Guaranty, or in the enforcement or attempted
enforcement thereof, shall be subject hereto and shall become a part of the
Guarantied Obligations and shall be paid to Lender by Guarantor, immediately
upon demand, together with interest thereon at the rate(s) provided for under
the Loan Agreement.

                                      -7-
<PAGE>

          14.  Liability.  Notwithstanding anything to the contrary elsewhere
               ---------
contained herein or in any Loan Document to which Guarantor is a Party, the
aggregate liability of Guarantor hereunder for payment and performance of the
Guarantied Obligations shall not exceed an amount which, in the aggregate, is
$1.00 less than that amount which if so paid or performed would constitute or
result in a "fraudulent transfer", "fraudulent conveyance", or terms of similar
import, under applicable state or federal Law, including without limitation,
Section 548 of the United States Bankruptcy Code.  The liability of Guarantor
hereunder is independent of any other guaranties at any time in effect with
respect to all or any part of the Guarantied Obligations, and Guarantor's
liability hereunder may be enforced regardless of the existence of any such
guaranties.  Any termination by or release of any guarantor in whole or in part
shall not affect the continuing liability of Guarantor hereunder, and no notice
of any such termination or release shall be required.  The execution hereof by
Guarantor is not founded upon an expectation or understanding that there will be
any other guarantor of the Guarantied Obligations.

          15.  WAIVER OF JURY TRIAL.  GUARANTOR AND LENDER EXPRESSLY WAIVE THEIR
               --------------------
RESPECTIVE RIGHTS TO A TRIAL BY JURY OF ANY CLAIM, DEMAND, ACTION OR CAUSE OF
ACTION BASED UPON OR ARISING OUT OF OR RELATED TO THIS GUARANTY, THE LOAN
AGREEMENT, THE OTHER LOAN DOCUMENTS OR THE TRANSACTIONS CONTEMPLATED HEREBY OR
THEREBY IN ANY ACTION, PROCEEDING OR OTHER LITIGATION OF ANY TYPE BROUGHT BY ANY
OF THE PARTIES AGAINST ANY OTHER PARTY OR PARTIES, WHETHER NOW EXISTING OR
HEREAFTER ARISING AND WHETHER WITH RESPECT TO CONTRACT CLAIMS, TORT CLAIMS, OR
OTHERWISE.  GUARANTOR AND LENDER AGREE THAT ANY SUCH CLAIM, DEMAND, ACTION OR
CAUSE OF ACTION SHALL BE TRIED BY A COURT TRIAL WITHOUT A JURY.  WITHOUT
LIMITING THE FOREGOING, THE PARTIES FURTHER AGREE THAT THEIR RESPECTIVE RIGHT TO
A TRIAL BY JURY IS WAIVED BY OPERATION OF THIS SECTION AS TO ANY ACTION,
COUNTERCLAIM OR OTHER PROCEEDING WHICH SEEKS, IN WHOLE OR IN PART, TO CHALLENGE
THE VALIDITY OR ENFORCEABILITY OF THIS GUARANTY, THE LOAN AGREEMENT OR THE OTHER
LOAN DOCUMENTS OR ANY PROVISION HEREOF OR THEREOF.  THIS WAIVER SHALL APPLY TO
ANY SUBSEQUENT AMENDMENTS, RENEWALS, SUPPLEMENTS OR MODIFICATIONS TO THIS
GUARANTY, THE LOAN AGREEMENT AND THE OTHER LOAN DOCUMENTS.  ANY PARTY HERETO MAY
FILE AN ORIGINAL COUNTERPART OR A COPY OF THIS SECTION WITH ANY COURT AS WRITTEN
EVIDENCE OF THE CONSENT OF THE SIGNATORIES HERETO TO THE WAIVER OF THEIR RIGHT
TO TRIAL BY JURY.

                                      -8-
<PAGE>

          16.  THIS GUARANTY SHALL BE GOVERNED BY, AND SHALL BE CONSTRUED AND
ENFORCED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF CALIFORNIA WITHOUT
REFERENCE TO THE CONFLICT OF LAWS OR CHOICE OF LAW PRINCIPLES THEREOF.

          IN WITNESS WHEREOF, Guarantor has executed this Guaranty by its duly
authorized officer as of the date first written above.

                                      "Guarantor"

                                      COAST RESORTS, INC.,
                                      a Nevada corporation


                                      By:___________________________
                                      Gage Parrish, Vice President
                                      and Chief Financial Officer


                                      Address:
                                      4500 West Tropicana Road
                                      Las Vegas, Nevada 89103
                                      702/365-7002 direct
                                      702/365-7111 general
                                      702/365-7566 FAX