<PAGE>
SUPPLEMENT DATED OCTOBER 1, 1997 TO
PROSPECTUS DATED MAY 1, 1997 FOR
INDIVIDUAL MODIFIED SINGLE PREMIUM DEFERRED VARIABLE ANNUITY CONTRACTS
ISSUED BY
NATIONWIDE LIFE INSURANCE COMPANY
THROUGH ITS
NATIONWIDE VARIABLE ACCOUNT-6
This Supplement updates certain information contained in your Prospectus.
Please read it and keep it with your Prospectus for future reference.
1. Effective November 1, 1997, the "UNDERLYING MUTUAL FUND ANNUAL EXPENSES"
provision of the Prospectus is amended by changing the Management Fees and
Other Expenses of the following Nationwide Separate Account Trust
underlying Mutual Fund options:
<TABLE>
<CAPTION>
- ---------------------------------------------------------------------------------------------------
Management Other Expenses Total Mutual
Fees Fund Expenses
- ---------------------------------------------------------------------------------------------------
<S> <C> <C> <C>
Nationwide Separate Account Trust - Government Bond Fund 0.55% 0.02% 0.57%
- ---------------------------------------------------------------------------------------------------
Nationwide Separate Account Trust - Money Market Fund 0.45% 0.02% 0.47%
- ---------------------------------------------------------------------------------------------------
</TABLE>
2. Effective November 1, 1997, the "EXAMPLE" in the Prospectus is amended to
reflect the following information:
<TABLE>
<CAPTION>
- ---------------------------------------------------------------------------------------------------------------------------
If you surrender your If you do not surrender If you annuitize your
Contract at the end of the your Contract at the end of Contract at the end of the
applicable time period the applicable time period applicable time period
- ---------------------------------------------------------------------------------------------------------------------------
1 3 5 10 1 3 5 10 1 3 5 10
Yr. Yrs. Yrs. Yrs. Yr. Yrs. Yrs. Yrs. Yr. Yrs. Yrs. Yrs.
- ---------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C> <C>
Nationwide Separate Account
Trust - Government Bond Fund 84 109 137 236 21 64 110 236 * 64 110 236
- ---------------------------------------------------------------------------------------------------------------------------
Nationwide Separate Account
Trust - Money Market Fund 83 106 131 225 20 61 104 225 * 61 104 225
- ---------------------------------------------------------------------------------------------------------------------------
</TABLE>
3. The following information is added to the "FEDERAL TAX CONSIDERATIONS"
section as the second provision:
PUERTO RICO
Under the Puerto Rico tax code, Distributions prior to Annuitization
are treated as nontaxable return of principal until the principal is fully
recovered; thereafter, all Distributions are fully taxable. Distributions
after Annuitization are treated as part taxable income and part nontaxable
return of principal. The amount excluded from gross income after
Annuitization is equal to the amount of the Distribution in excess of 3% of
the total Purchase Payments paid, until an amount equal to the total
Purchase Payments paid has been excluded; thereafter, the entire
Distribution is included in gross income. Puerto Rico does not impose an
early withdrawal penalty tax. Generally, Puerto Rico does not require
income tax to be withheld from Distributions of income. A personal tax
advisor should be consulted.
4. Effective November 3, 1997, the "SYSTEMATIC WITHDRAWALS" provision is
amended to reflect the following change in the table located on page 30 of
the Prospectus:
Contract Owner's Age Percentage of Contract Value
-------------------- ----------------------------
Under 59 1/2 5%
59 1/2 to 62 7%
62 to 65 8%
65 to 75 10%
75 and Over 13%
