<PAGE>

                             EXHIBIT (4)(c)(xiii)

                           FORM OF TAX RELIEF RIDER
<PAGE>

                  [LETTERHEAD OF TRANSAMERICA LIFE COMPANIES]

                        ADDITIONAL DEATH BENEFIT RIDER

We issued this rider as a part of the contract to which it is attached.

This rider will pay an Additional Death Benefit amount equal to a percentage of
the gains accumulated in the contract since the rider was added.  This
additional death benefit will be paid whenever death proceeds are payable on the
base contract to which this rider is attached.

This rider will be considered terminated when the contract is annuitized or
surrendered, or an additional death benefit is paid under the terms of this
rider.  You may also terminate this benefit at any time by notifying us at our
service center.  Once terminated, this rider may be re-elected.  However, a new
rider will be issued and the Additional Death Benefit amount will be re-
determined.

Contract Number:                        [123456]
Rider Date:                             [11-14-2000]
Additional Death Benefit Factor:        [10.00]%
Rider Fee Percentage:                   [0.75]%

DEFINITIONS

Rider Anniversary
The anniversary of the Rider Date for each year the rider remains in force.

Rider Date
The date that this rider is added to the contract.

Rider Earnings
The contract gains accrued and not previously withdrawn since the Rider Date.
On a given date, this amount is equal to: the death proceeds of the base
contract; minus the Account Value of the base contract on the Rider Date; minus
Purchase Payments made after the rider date; plus amounts withdrawn from the
Account Value after the Rider Date that exceed the Rider Earnings on the date of
the withdrawal.

ADDITIONAL DEATH BENEFIT AMOUNT
If death proceeds are payable under the terms of the base contract to which this
rider is attached, this rider will pay an Additional Death Benefit equal to the
Additional Death Benefit Factor multiplied by the Rider Earnings on the date
used to calculate the death proceeds.

ADDITIONAL DEATH BENEFIT PREMIUM
We will deduct a fee from the Account Value on each Rider Anniversary and a pro-
rated fee on the termination date of the rider.  The Rider Fee is equal to the
Account Value at the time the fee is deducted, multiplied by the Rider Fee
Percentage shown on the first page of this rider.  The fee will be deducted from
each subaccount and fixed account in proportion to the amount of Account Value
in each account.  This fee will not be deducted after the contract is
annuitized.


 RTP 3 401

<PAGE>

SPOUSAL CONTINUATION
If a death occurs and the deceased's spouse, if any, is continuing the base
contract in lieu of receiving the death proceeds, the continuing spouse has the
following options:

 .    Terminate the Additional Death Benefit Rider and receive a one-time Account
     Value increase equal to the amount of the Additional Death Benefit. All
     future surrender charges on this amount, if any, will be waived.

 .    Continue the Additional Death Benefit Rider without the one-time Account
     Value increase. An Additional Death Benefit Amount would then be paid upon
     the death of the continuing spouse.



Additional Death Benefit Example:

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------------------------
Additional Death Benefit Example Assumptions:
----------------------------------------------------------------------------------------------------------------------------
<S>                                                                                                             <C>
Account Value at rider issue                                                                                        $100,000
Purchase Payments after rider issue                                                                                 $ 25,000
Rider Earnings withdrawn                                                                                            $ 35,000
Death proceeds on base contract                                                                                     $225,000
Additional Death Benefit Factor                                                                                     10%

----------------------------------------------------------------------------------------------------------------------------
Additional Death Benefit Calculations:
----------------------------------------------------------------------------------------------------------------------------
Rider Earnings = death proceeds - Account Value on the Rider Date - Purchase Payments after the Rider Date +
 withdrawals that exceed Rider Earnings on date of withdrawal = $225,000 - $100,000 - $25,000 + $0                  $100,000

Additional Death Benefit Amount = Additional Death Benefit Factor * Rider Earnings = 10% * $100,000                 $ 10,000

Total death proceeds = death proceeds on base contract + Additional Death Benefit Amount = $225,000 + $10,000       $235,000
----------------------------------------------------------------------------------------------------------------------------
</TABLE>



                       Signed for us at our home office.


          /s/ James W. Dederer                 /s/ Ron F. Wagley

                SECRETARY                          PRESIDENT


 RTP 3 401 (2)