EXHIBIT 2




                         AMENDMENT TO RIGHTS AGREEMENT


     AMENDMENT, dated April 28, 2002 (this "Amendment"), to the Rights
Agreement, dated as of March 6, 2002 (the "Rights Agreement"), between HNC
Software Inc., a Delaware corporation ("Company"), and EquiServe Trust Company,
N.A., as Rights Agent ("Rights Agent").

     WHEREAS, concurrently with the execution and delivery of this Amendment,
Company, Fair, Isaac and Company, Incorporated, a Delaware corporation
("Acquirer"), and Northstar Acquisition Inc., a Delaware corporation and
wholly-owned subsidiary of Acquirer ("Merger Sub"), have entered into an
Agreement and Plan of Merger (the "Merger Agreement"), pursuant to which
Acquirer will cause Merger Sub to merge with and into the Company with the
Company continuing as the surviving corporation (the "Merger"), and the Board of
Directors of the Company has approved the Merger Agreement, the Merger, and this
Amendment;

     WHEREAS, Section 27 of the Rights Agreement provides that (i) prior to the
time any Person (as defined in the Rights Agreement) becomes an Acquiring Person
(as defined in the Rights Agreement), Company may amend the Rights Agreement as
Company deems necessary or desirable, including to modify or amend the
definition of Acquiring Person set forth in Section 1(a) of the Rights
Agreement, and (ii) such an amendment will be evidenced by a writing signed by
the Company and the Rights Agent; provided, however, that Rights Agent shall not
be obligated to enter into any amendment or supplement to the Rights Agreement
that, in the opinion of the Rights Agent, may materially adversely affect the
rights, duties, and liabilities to the Company or immunities to the Company of
the Rights Agent; and

     WHEREAS, pursuant to Section 27 of the Rights Agreement, the Board of
Directors of Company has determined that an amendment to the Rights Agreement as
set forth herein is necessary and desirable in connection with the foregoing and
the Company desires to evidence such amendment in writing.

     THEREFORE, in consideration of the foregoing and the mutual agreements set
forth herein, the parties agree as follows:

     1.   Company certifies to Rights Agent that this Amendment will not
materially adversely affect the rights, duties, liabilities to the Company or
immunities to the Company of the Rights Agent and that Rights Agent is entitled
to rely upon such certification in forming its opinion as to whether this
Amendment would materially adversely affect the rights, duties, liabilities to
the Company or immunities to the Company of the Rights Agent.

     2.   Section 1(a) of the Rights Agreement is hereby amended by inserting
the following sentence at the end of the definition of "Acquiring Person":

          "(C)  Neither Fair Isaac and Company, Incorporated, a Delaware
     corporation ("Acquirer"), nor any of its Subsidiaries, Affiliates or
     Associates, shall be or become an Acquiring Person as a result of the
     execution, delivery or performance, or public announcement, of the
     Agreement and Plan of Merger among Company, Acquirer and Northstar
     Acquisition Inc. dated as of April 28, 2002, as such may be amended, (the
     "Merger Agreement"), or the consummation of any of the transactions
     contemplated thereby."

     3.   Section 7(a) of the Rights Agreement is hereby amended by replacing
the section in its entirety with the following:

          "(a)  The registered holder of any Right Certificate may exercise the
     Rights evidenced thereby (except as otherwise provided herein) in whole or
     in part at any time after the Distribution Date upon surrender of the Right
     Certificate, with the form of election to purchase on the reverse side
     thereof duly executed, to the Rights Agent at the office of the Rights
     Agent, together with payment of the Purchase Price for each one
     one-hundredth of a Preferred Share as to which the Rights are exercised and
     payment of all taxes and governmental charges required to be paid by the
     holder of such Right Certificate as provided in Section 9 hereof, at or
     prior to the earliest of (i) the Close of Business on March 21, 2012, (ii)
     the time at which the Rights are redeemed as provided in Section 23 hereof
     (the "Redemption Date"), (iii) the time at which such Rights are exchanged
     as provided in Section 24 hereof, or (iv) immediately prior to the
     Effective Time (as defined in the Merger Agreement), which Effective Time
     the Company will notify the Rights Agent in writing of and the Rights Agent
     shall not be deemed to have knowledge of the Effective Time unless and
     until it has received such written notification (the first to occur of (i)
     through (iv) hereof (inclusive) being herein referred to as the "Final
     Expiration Date")."

     4.   This Amendment shall be effective immediately prior to the execution
of the Merger Agreement; provided, however, that this Amendment will be of no
further force or effect upon the termination of the Merger Agreement in
accordance with its terms.  The Company will provide the Rights Agent with
prompt notice of either the consummation of the transactions contemplated by the
Merger Agreement or the termination of this Amendment pursuant to this section.

     5.   This Amendment shall be governed by, and construed in accordance with
the laws of the State of Delaware applicable to contracts to be made and
performed entirely within such state.  If any term of this Amendment is held by
a court of competent jurisdiction or other competent authority to be invalid or
unenforceable, the remainder of the terms hereof shall remain in full force and
effect, and this Amendment shall be construed in order to give the maximum
effect to the remaining terms and intent hereof.  Acquirer, its Subsidiaries,
Affiliates and Associates (each as defined in the Rights Agreement) are intended
third party beneficiaries of the terms hereof.  This Amendment may be executed
in one or more counterparts, all of which shall together constitute one
instrument.


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                                       2

     IN WITNESS WHEREOF, the parties have cause this Amendment to be executed by
their duly authorized officers as of the date first written above.


                                        HNC SOFTWARE INC.


                                        By: /s/ John Mutch
                                           ---------------------------
                                        Name: John Mutch
                                        Title: Chief Executive Officer


                                        EQUISERVE TRUST COMPANY, N.A., AS
                                        RIGHTS AGENT


                                        By: /s/ Michael J. Connor
                                           ---------------------------
                                        Name: Michael J. Connor
                                        Title: Managing Director, Client Admin.




               [SIGNATURE PAGE TO AMENDMENT TO RIGHTS AGREEMENT]