Exhibit No. EX-99.a.3


                      DFA INVESTMENT DIMENSIONS GROUP INC.


                      ARTICLES SUPPLEMENTARY TO THE CHARTER

     DFA INVESTMENT  DIMENSIONS  GROUP INC., a Maryland  corporation  having its
principal office in Baltimore,  Maryland  (hereinafter called the "Corporation")
and registered  under the Investment  Company Act of 1940, as amended (the "1940
Act"),  as an open-end  management  investment  company,  hereby  certifies,  in
accordance  with the  requirements  of Section 2-208 and Section  2-208.1 of the
Maryland  General  Corporation  Law, to the State  Department of Assessments and
Taxation of Maryland that:

     FIRST:  The  Corporation  has  authority  to issue a total  of Six  Billion
(6,000,000,000) shares of stock, with a par value of One Cent ($0.01) per share,
having an aggregate par value of Sixty  Million  Dollars  ($60,000,000),  all of
which shall be considered common stock. The allocation of shares of common stock
to each of its thirty-six  existing  classes of common stock (each a "Class" and
collectively, the "Classes") is as follows:

                                                        Number of Shares of Common Stock
                                                          (par value $0.01 per share)
Class Designation                                                  Allocated

The U.S. Large Company Portfolio Shares                           200,000,000

U.S. Micro Cap Portfolio Shares                                   300,000,000

The DFA One-Year Fixed Income Portfolio Shares                    300,000,000

The DFA Five-Year Government Portfolio Shares                     100,000,000

The United Kingdom Small Company Portfolio Shares                  20,000,000

The Japanese Small Company Portfolio Shares                        50,000,000

The Continental Small Company Portfolio Shares                     50,000,000

The DFA Intermediate Government Fixed Income
Portfolio Shares                                                  100,000,000

The DFA Five-Year Global Fixed Income Portfolio Shares            100,000,000

The Pacific Rim Small Company Portfolio Shares                     50,000,000

The Large Cap International Portfolio Shares                      150,000,000

U.S. Small Cap Portfolio Shares                                   100,000,000

U.S. Small Cap Value Portfolio Shares                             400,000,000

The U.S. Large Cap Value Portfolio Shares                         200,000,000

The DFA Real Estate Securities Portfolio Shares                   100,000,000

LWAS/DFA International High Book to Market Portfolio
Shares                                                            100,000,000

The Emerging Markets Portfolio Shares                             100,000,000

DFA International Small Cap Value Portfolio Shares                200,000,000

VA Large Value Portfolio Shares                                    50,000,000

VA Global Bond Portfolio Shares                                    50,000,000

VA Small Value Portfolio Shares                                    50,000,000

VA International Value Portfolio Shares                            50,000,000

VA International Small Portfolio Shares                            50,000,000

The VA Short-Term Fixed Portfolio Shares                           50,000,000

Enhanced U.S. Large Company Portfolio Shares                      100,000,000

DFA Two-Year Global Fixed Income Portfolio Shares                 200,000,000

International Small Company Portfolio Shares                      100,000,000

Emerging Markets Small Cap Portfolio Shares                       100,000,000

U.S. Small XM Value Portfolio Shares                              100,000,000

Emerging Markets Value Portfolio Shares                           100,000,000

Tax-Managed U.S. Small Cap Value Portfolio Shares                 100,000,000

Tax-Managed U.S. Small Cap Portfolio Shares                       100,000,000

Tax-Managed U.S. Marketwide Value Portfolio Shares                100,000,000

Tax-Managed DFA International Value Portfolio Shares              100,000,000

Tax-Managed U.S. Equity Portfolio Shares                          100,000,000

DFA Short-Term Municipal Bond Portfolio Shares                    100,000,000

     The  allocation  and  classification  of  shares  of  common  stock  of the
Corporation to the Class designated as the U.S. Small Cap Value Portfolio Shares
into two sub-classes of common stock (each a "Sub-Class," and collectively,  the
"Sub-Classes") is as follows:

                                                        Number of Shares of Common Stock
                                                          (par value $0.01 per share)
Sub-Class Designation                                              Allocated

U.S. Small Cap Value Portfolio Shares-Investor Class              300,000,000

U.S. Small Cap Value Portfolio Shares-Class R                     100,000,000

     SECOND:  The Board of Directors of the Corporation has adopted a resolution
classifying  and  allocating  One Hundred  Million  (100,000,000)  shares of the
unallocated  and unissued  common stock with a par value of One Cent ($0.01) per
share of the Corporation to a new class of common stock  designated as "Emerging
Markets Core Equity Portfolio Shares."

     THIRD:  Following the aforesaid  classification  and allocation,  the total
number of shares of common stock which the Corporation is authorized to issue is
Six Billion  (6,000,000,000)  shares,  with a par value of One Cent  ($0.0l) per
share and an aggregate par value of Sixty Million Dollars ($60,000,000), and the
allocation of shares to each of the thirty-seven Classes is as follows:

                                                        Number of Shares of Common Stock
                                                          (par value $0.01 per share)
                        Class Designation                          Allocated

The U.S. Large Company Portfolio Shares                           200,000,000

U.S. Micro Cap Portfolio Shares                                   300,000,000

The DFA One-Year Fixed Income Portfolio Shares                    300,000,000

The DFA Five-Year Government Portfolio Shares                     100,000,000

The United Kingdom Small Company Portfolio Shares                  20,000,000

The Japanese Small Company Portfolio Shares                        50,000,000

The Continental Small Company Portfolio Shares                     50,000,000

The DFA Intermediate Government Fixed Income Portfolio
Shares                                                            100,000,000

The DFA Five-Year Global Fixed Income Portfolio Shares            100,000,000

The Pacific Rim Small Company Portfolio Shares                     50,000,000

The Large Cap International Portfolio Shares                      150,000,000

U.S. Small Cap Portfolio Shares                                   100,000,000

U.S. Small Cap Value Portfolio Shares                             400,000,000

The U.S. Large Cap Value Portfolio Shares                         200,000,000

The DFA Real Estate Securities Portfolio Shares                   100,000,000

LWAS/DFA International High Book to Market Portfolio
Shares                                                            100,000,000

The Emerging Markets Portfolio Shares                             100,000,000

DFA International Small Cap Value Portfolio Shares                200,000,000

VA Large Value Portfolio Shares                                    50,000,000

VA Global Bond Portfolio Shares                                    50,000,000

VA Small Value Portfolio Shares                                    50,000,000

VA International Value Portfolio Shares                            50,000,000

VA International Small Portfolio Shares                            50,000,000

The VA Short-Term Fixed Portfolio Shares                           50,000,000

Enhanced U.S. Large Company Portfolio Shares                      100,000,000

DFA Two-Year Global Fixed Income Portfolio Shares                 200,000,000

International Small Company Portfolio Shares                      100,000,000

Emerging Markets Small Cap Portfolio Shares                       100,000,000

U.S. Small XM Value Portfolio Shares                              100,000,000

Emerging Markets Value Portfolio Shares                           100,000,000

Tax-Managed U.S. Small Cap Value Portfolio Shares                 100,000,000

Tax-Managed U.S. Small Cap Portfolio Shares                       100,000,000

Tax-Managed U.S. Marketwide Value Portfolio Shares                100,000,000

Tax-Managed DFA International Value Portfolio Shares              100,000,000

Tax-Managed U.S. Equity Portfolio Shares                          100,000,000

DFA Short-Term Municipal Bond Portfolio Shares                    100,000,000

Emerging Markets Core Equity Portfolio Shares                     100,000,000

     The  allocation  and  classification  of  shares  of  common  stock  of the
Corporation to the Class designated as the U.S. Small Cap Value Portfolio Shares
among its two Sub-Classes is as follows:

                                                        Number of Shares of Common Stock
                                                          (par value $0.01 per share)
Sub-Class Designation                                              Allocated

U.S. Small Cap Value Portfolio Shares-Investor Class              300,000,000

U.S. Small Cap Value Portfolio Shares-Class R                     100,000,000

     FOURTH:  A description of the shares of the U.S. Small Cap Value  Portfolio
Class  of  Shares  and the  Sub-Classes  thereof,  as well  as any  other  Class
hereafter  divided into Sub-Classes,  unless otherwise  provided in the Articles
Supplementary  creating  Sub-Classes  with  respect  to one or more  Classes  of
Shares,  with the  preferences,  conversion  and other  rights,  voting  powers,
restrictions,   limitations  as  to  dividends,  qualifications  and  terms  and
conditions  of  redemption  as set or changed by the Board of  Directors  of the
Corporation, is as follows:

     The holder of each share of each Class and  Sub-Class  shall be entitled to
one vote for each full share, and a fractional vote for each fractional share of
stock  then  standing  in his or her name on the books of the  Corporation.  All
shares of the Classes and  Sub-Classes  then issued and outstanding and entitled
to vote, irrespective of Class or Sub-Class, shall be voted in the aggregate and
not by Class or Sub-Class,  except: (1) when otherwise expressly provided by the
Maryland  General  Corporation  Law; (2) when  required by the 1940 Act,  shares
shall be voted by Class or  Sub-Class;  and (3) when a matter  to be voted  upon
does not affect any  interest  of a  particular  Class or  Sub-Class,  then only
shareholders  of the affected  Class(es) or  Sub-Class(es)  shall be entitled to
vote thereon.

     Each share of each Class and Sub-Class shall have the following preferences
and special rights, restrictions, and limitations:

          (1) All  consideration  received by the  Corporation  for the issue or
     sale of stock  of a Class  (or a  Sub-Class),  together  with  all  income,
     earnings,  profits, and proceeds thereof, and any funds or payments derived
     from any  reinvestment  of such  proceeds in whatever form the same may be,
     shall irrevocably belong to such Class (or Sub-Class),  subject only to the
     rights of creditors.

          (2) Dividends or  distributions  on shares of a Class (or a Sub-Class)
     and  redemptions  of such  Class (or  Sub-Class)  shall be paid only out of
     earnings,  surplus,  or other lawfully  available  assets belonging to such
     Class (or Sub-Class).

          (3) The  Corporation  may deduct from the  proceeds of  redemption  of
     shares of each  Class  (or  Sub-Class)  the cost  incurred  in  liquidating
     investment  securities  to pay  redemptions  in  cash as set  forth  in the
     By-Laws.

          (4) In the event of the liquidation or dissolution of the Corporation,
     holders of each Class (or  Sub-Class)  shall be entitled  to receive,  as a
     Class (or a Sub-Class),  out of the assets of the Corporation available for
     distribution to  shareholders,  but other than general assets not belonging
     to any particular Class (or Sub-Class),  the assets belonging to such Class
     (or Sub-Class);  and the assets so distributable to such shareholders shall
     be distributed  among such shareholders in proportion to the asset value of
     such shares.  In addition,  such holders shall be entitled to receive their
     proportionate share of assets of the Corporation which do not belong solely
     to any  particular  Class (or  Sub-Class),  as  determined  by the Board of
     Directors.

          (5) The assets belonging to each Class (or Sub-Class) shall be charged
     with the  liabilities  in respect to such Class (or  Sub-Class),  and shall
     also  be  charged  with  their  share  of the  general  liabilities  of the
     Corporation as determined by the Board of Directors, and such determination
     shall be conclusive for all purposes.

     FIFTH:  The shares aforesaid have been duly classified and allocated by the
Board of  Directors  pursuant  to  authority  contained  in the  charter  of the
Corporation.

     SIXTH: The undersigned Vice President  hereby  acknowledges  these Articles
Supplementary  to the Charter to be the corporate act of the Corporation and, as
to all matters or facts required to be verified under oath, the undersigned Vice
President  acknowledges  that,  to the best of her  knowledge,  information  and
belief, these matters and facts are true in all material respects, and that this
statement is made under the penalties of perjury.

     IN WITNESS WHEREOF,  the Corporation has caused these Articles to be signed
in its name and on its  behalf  by its Vice  President  and  attested  to by its
Assistant Secretary on this 6th day of January, 2004.


ATTEST:                                 DFA INVESTMENT DIMENSIONS GROUP INC.


By:    /s/Valerie A. Brown              By:    /s/Catherine L. Newell
       Valerie A. Brown                        Catherine L. Newell
       Assistant Secretary                     Vice President