Exhibit 5.1


                                December 22, 1999

Rambus Inc.
2465 Latham Street
Mountain View, California  94040

         Re:  Registration Statement on Form S-8

Ladies and Gentlemen:

         We have examined the Registration Statement on Form S-8 (the
"Registration Statement") to be filed by Rambus Inc., a Delaware corporation
(the "Registrant" or "you"), with the Securities and Exchange Commission on or
about December 22, 1999, in connection with the registration under the
Securities Act of 1933, as amended, of an aggregate of 2,128,840 shares of your
Common Stock, $0.001 par value (the "Shares"), reserved for issuance pursuant to
the 1997 Stock Plan, the 1997 Employee Stock Purchase Plan and the 1999
Nonstatutory Stock Option Plan (collectively, the "Plans"). As your legal
counsel, we have reviewed the actions proposed to be taken by you in connection
with the proposed sale and issuance of the Shares by the Registrant under the
Plans. We assume that the consideration received by you in connection with each
issuance of Shares will include an amount in the form of cash, services rendered
or property that exceeds the greater of (i) the aggregate par value of such
Shares or (ii) the portion of such consideration determined by the Company's
Board of Directors to be "capital" for purposes of the Delaware General
Corporation Law.

         It is our opinion that, upon completion of the proceedings being taken,
or contemplated by us, as your counsel, to be taken prior to the issuance of the
Shares pursuant to the Registration Statement and the Plans, including the
proceedings being taken in order to permit such transaction to be carried out in
accordance with applicable state securities laws, the Shares, when issued and
sold in the manner described in the Registration Statement and in accordance
with the resolutions adopted by the Board of Directors of the Company, will be
legally and validly issued, fully paid and nonassessable.

         We consent to the use of this opinion as an exhibit to the Registration
Statement, and further consent to the use of our name wherever appearing in the
Registration Statement and any amendments thereto.

                                        Very truly yours,

                                        WILSON SONSINI GOODRICH & ROSATI
                                        Professional Corporation

                                        /s/ WILSON SONSINI GOODRICH & ROSATI