<PAGE>

                                                                   EXHIBIT 10.12

ALL SECTIONS MARKED WITH ASTERISKS REFLECT PORTIONS WHICH HAVE BEEN REDACTED AND
FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION BY THQ INC. AS PART
OF A REQUEST FOR CONFIDENTIAL TREATMENT.

           PLAYSTATION(R) LICENSED PUBLISHER - SUPPLEMENTAL AGREEMENT

           This Agreement is entered into the 25 day of June 1998 and
is supplemental to the Licensed Publisher Agreement ("LPA") of even date
                            herewith by and between


                       SONY COMPUTER ENTERTAINMENT EUROPE
             (a Division of SONY COMPUTER ENTERTAINMENT UK LIMITED)
                      of 25 Golden Square, London W1R 6LU
                      (hereinafter referred to as "SCEE")

                                     -and-

                           THQ INTERNATIONAL LIMITED
             of Dukes Court, Duke Street, Woking, Surrey GU21 5BH
                    (hereinafter referred to as "Publisher")
                         PUBLISHER AUTHORISATION #:138

In consideration of the undertakings, representations and warranties given
herein, and of other good and valuable consideration the receipt and sufficiency
of which is acknowledged, Publisher and SCEE hereby agree as follows:

Rental

(1)  The provisions of LPA Clause 3.3 shall be modified to the effect that
     Publisher shall be entitled to undertake or authorise the rental or lending
     of PlayStation Software products within the Licensed Territory.

(2)  If the Master Disc content of the Rental version of any product varies from
     that of the retail version (if any) of the same product, then the Rental
     version will be allocated a different SCEE Product Code.

(3)  Subject to (2) above, all Rental products (and associated materials) shall
     be subject to the Specifications (as defined in the LPA and set forth in
     the SCEE's Specifications & Procedures manual, as amended from time to
     time), and to the Procedures (specifically including, but without
     limitation, those relating to submissions, evaluation and approvals) also
     set forth in such manual, including specifically but without limitation any
     such Specifications and/or Procedures which relate specifically to Rental
     products.

(4)  The Manufacture of Licensed Products & Associated Materials provisions of
     LPA Clause 6, and the Purchase Price provisions of LPA Clauses 7.1 to 7.3
     (but not the Returns provisions of LPA Clause 7.4) and of LPA Schedule 2
     (but not Schedule 2[R]), shall apply to all Rental products.

(5)  Publisher warrants and represents that it shall obtain all necessary
     consents and clearances from, and make all necessary payments to, third
     parties whose rights in respect of Rental products are protected under the
     European Council Rental Rights Directive and the corresponding national
     implementing legislation of European Union member states (and any similar
     legislation in any other country of the Licensed Territory); [**]


[*]  Confidential portion omitted and filed separately with the Securities and
     Exchange Commission.


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(6)     The undertaking or authorising of any renting or lending of PlayStation
        Software except as authorised herein and subject to Specifications
        and/or Procedures (as referred to in (3) above) shall continue to be a
        breach of the LPA. The provisions of LPA Clause 13.2 will apply to any
        such breach and the repetition of prior material breach provisions of
        LPA Clause 13.1(i) will apply to the repetition of any such breach.

Demonstration & Promotion Discs

(1)     The production of Demo Discs (for use as magazine covermounts and
        similar or related purposes) and of Promo Discs (for use as salesman's
        samples and similar or related purposes) will be available on a
        not-for-retail basis.

(2)     All Demo & Promo Discs (and associated materials) shall be subject to
        the Specifications (as defined in the LPA and set forth in SCEE's
        Specifications & Procedures manual, as amended from time to time), and
        to the Procedures (specifically including, but without limitation, those
        relating to submissions, evaluation and approvals) also set forth in
        such manual, including specifically but without limitation any such
        Specifications and/or Procedures which relate specifically to Demo
        and/or Promo Discs.

(3)     The Manufacture of Licensed Products & Associated Materials provisions
        of LPA Clause 6, and, subject as provided below, the Purchase Price
        provisions of LPA Clauses 7.1 to 7.3 (but not the Returns provisions of
        LPA Clause 7.4 and Schedule 2([R]), shall apply to all Demo & Promo
        Discs. However, the Purchase Price for Demo & Promo Discs will be as
        set forth in Exhibits A and B hereto respectively (and not as set forth
        in LPA Schedule 2).

PlayStation Platinum

(1)     The production of inventory in the PlayStation Platinum range will be
        available for qualifying PlayStation Software products.

(2)     The qualifying criteria for admission to the PlayStation Platinum range
        is [**] units or more of aggregate Purchase Orders (excluding for Rental
        inventory and Demo & Promo Discs) in [**].

        SCEE reserves the right to review and adjust the qualifying criterion
        by reference to the then installed base of PlayStation consoles in the
        PAL territories from time to time.

(3)     The initial Purchase Order for PlayStation Platinum inventory of any
        given PlayStation Software product may not normally be placed less than
        [**] following the placing of the first Purchase Order for the same
        product.

(4)     All PlayStation Platinum inventory (and associated materials) shall be
        subject to the Specifications (as defined in the LPA and set forth in
        SCEE's Specifications & Procedures manual, as amended from time to
        time), and to the Procedures (specifically including, but without
        limitation, those relating to submissions, evaluation and approvals)
        also set forth in such manual, including specifically but without
        limitation any such Specifications and/or Procedures which relate
        specifically to the PlayStation Platinum range.

(5)     The Manufacture of Licensed Products & Associated Materials provisions
        of LPA Clause 6, and, subject as provided below, the Purchase Price
        provisions of LPA Clauses 7.1 to 7.3 (but not the Returns provisions of
        LPA Clause 7.4 and Schedule 2[R]), shall apply to all PlayStation
        Platinum


                                                                          Page 2

[*]  Confidential portion omitted and filed separately with the Securities and
     Exchange Commission.
<PAGE>
     inventory. However, the Purchase Price for all PlayStation Platinum
     inventory will be as set forth in Exhibit C hereto (and not as set forth
     in LPA Schedule 2).

SUBJECT only to the foregoing, all the terms and conditions of the LPA shall
apply to Rental, Demo & Promo Discs and shall continue in full force and effect.

IN WITNESS WHEREOF the parties hereto have caused this Supplemental Agreement
to be executed as of the date first above written.

SONY COMPUTER ENTERTAINMENT EUROPE      THQ INTERNATIONAL LIMITED
(a Division of SONY COMPUTER
ENTERTAINMENT UK LIMITED)


/s/ CHRISTOPHER DEERING                 /s/ TIM WALSH
----------------------------------      ----------------------------------
Signature                               Signature

Christopher Deering                     Tim Walsh
----------------------------------      ----------------------------------
Name                                    Signatory's Name (please print)

President                               V P International
----------------------------------      ----------------------------------
Title                                   Title


                                   Exhibit A

                           PURCHASE PRICE - DEMO DISC

For Demo Disc product unit comprising:

-  1 (one) black PlayStation interactive software Disc

-  standard Demo Disc Label

-  optional maxicase (audio CD Single jewel case)
   or plain paper pochette, including assembly

                                                   [**]

-  PlayStation Disc mastering
   (initial order only)                            [**]

Minimum order quantity - initial order             [**]

                       - reorders                  [**]

For multi-colour Disc Label and/or White Base Underlay, the following charges
(in addition to the per unit Purchase Price for standard 2-colour Disc Label)
will apply:

Multi-Colour Disc Label            3-colour        [**]
                                   4-colour        [**]
                                   5-colour        [**]
                                   6-colour        [**]

White Base Underlay                                [**]



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[*]  Confidential portion omitted and filed separately with the Securities and
     Exchange Commission.
<PAGE>

                                   Exhibit B

                          PURCHASE PRICE - PROMO DISC

For Promo Disc product unit comprising:

-    1 (one) black PlayStation interactive software Disc

-    standard Promo Disc Label

-    maxicase (audio CD Single jewel case), including assembly
                                                               [**]

-    PlayStation Disc mastering                                [**]

-    For each additional Disc in a Multi-Disc Promo            [**]

Minimum order quantity  - Initial order                        [**]

                        - reorders                             [**]

Maximum order quantity (single order or aggregate)             [**]


                                   Exhibit C

                     PURCHASE PRICE - PLAYSTATION PLATINUM

For 1-Disc PlayStation Platinum product unit comprising:

-    1 (one) black PlayStation interactive software Disc

-    1 x PlayStation Platinum Disc Label

-    standard PlayStation jewel case, including assembly

     -  Purchase Orders placed [**]                            [**]

     -  Purchase Orders placed [**]                            [**]


For Multi-Disc PlayStation Platinum product unit (up to 6 Discs) comprising:

-    applicable number of black PlayStation interactive software Discs

-    applicable number of PlayStation Platinum Disc Labels

-    applicable multi-tray PlayStation jewel case, including assembly

     - Purchase Orders placed [**]                          [**]

     - Purchase Orders placed [**]                          [**]

-    PlayStation Disc Mastering                             [**]

Minimum order quantity - initial order and reorders         [**]

For more than 6-Disc PlayStation Platinum product units -   [**]

L. equal pounds sterling


[*]  Confidential portion omitted and filed separately with the Securities and
     Exchange Commission.


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