<PAGE>
                                                                   EXHIBIT 10.12

                                  AMENDMENT TO
                            THE EMPLOYMENT AGREEMENT

                  This Amendment to the Employment Agreement (this "Amendment"),
effective as of December 11, 2001, is made by and between Penton Media, Inc., a
Delaware corporation (the "Company") and David Nussbaum (the "Executive"), in
order to amend the Employment Agreement made as of June 16, 1998 (the
"Agreement").

                  NOW THEREFORE, the undersigned parties hereby amend the
Agreement as follows:

1.       Paragraph 3 of the Agreement is hereby amended to add the following new
         paragraph 3(i) at the end thereof:

         "(i) 2001 LIFE INSURANCE BENEFITS. The Company shall use its best
         efforts to purchase (as soon as reasonably practicable after December
         1, 2001) and maintain in effect until the first date (the "Payoff
         Date") that there is no amount due from Executive to the Company under
         any Promissory Note in effect on December 11, 2001 issued by Executive
         to the Company (the "Note"), additional term life insurance coverage in
         an amount equal to at least $1,070,000. If the Company is unable to
         procure or maintain such life insurance on behalf of Executive, it
         shall provide, from its own funds, a lump sum death benefit equal to
         the term life insurance coverage amount provided for in the preceding
         sentence, which shall be payable to Executive's designated beneficiary
         or beneficiaries in the event of Executive's death prior to the Payoff
         Date."

2.       Paragraph 3 of the Agreement is hereby amended to add the following new
         paragraph 3(j) at the end thereof:

         "(j) 2001 DISABILITY BENEFITS. The Company shall use its best efforts
         to purchase (as soon as reasonably practicable after December 1, 2001)
         and maintain in effect until the Payoff Date, supplementary long-term
         disability coverage in an amount equal to at least $1,070,000. If the
         Company is unable to procure or maintain such supplementary long-term
         disability coverage on behalf of Executive, it shall provide, from its
         own funds, a lump sum disability benefit equal to the long-term
         disability insurance coverage amount provided for in the preceding
         sentence, which shall be payable to Executive in the event of
         Executive's disability prior to the Payoff Date."

3.       Paragraph 3 of the Agreement is hereby amended to add the following new
         paragraph 3(k) at the end thereof:

         "(k)     ADDITIONAL 2001 BENEFITS.

                  (i)      The Company shall pay to Executive each year,
                           regardless of whether this Agreement has been
                           terminated, a payment (the "(k)(i) Gross Up Payment")
                           in an amount equal to the total of all income taxes
                           imposed on

<PAGE>

                           Executive as a result of (A) the Company's
                           provision of life and disability insurance coverage
                           as set forth in the first sentence of each of
                           paragraphs 3(i) and 3(j) above; (B) imputed income to
                           Executive with respect to the Notes; and (C) the
                           (k)(i) Gross Up Payment; and

                  (ii)     The Company shall pay to Executive, regardless of
                           whether this Agreement has been terminated, a payment
                           (the "(k)(ii) Gross Up Payment") in an amount equal
                           to the total of all income taxes imposed on Executive
                           as a result of (A)(i) the issuance of the Deferred
                           Shares to Executive on an accelerated basis following
                           a Change of Control, a Termination without Cause, a
                           Termination by Executive for Good Reason, Executive's
                           involuntary Retirement, or the death or disability of
                           Executive or (ii) any other issuance of the Deferred
                           Shares to Executive, if a Change of Control occurs
                           prior to the payment in full of the Notes; and (B)
                           the (k)(ii) Gross Up Payment.

                  (iii)    In the event that the excise tax under Section 4999
                           of the Internal Revenue Code applies to the issuance
                           of the Deferred Shares to the Executive or the
                           (k)(ii) Gross Up Payment, and if the sum of (A) the
                           value of the Deferred Shares at the time of such
                           Change of Control, reduced by such excise tax, plus
                           (B) the value of the Purchased Shares at the time of
                           such Change of Control, plus (C) the proceeds of any
                           life insurance or disability insurance (or Company
                           provided death benefit or disability benefit)
                           described in paragraphs 3(i) and 3(j) above received
                           by or with respect to the Executive at the time of or
                           before such Change of Control (the sum of (A), (B)
                           and (C) being referred to as the "Loan Payments") is
                           less than the amount due and owing by the Executive
                           under the Note at the time of the Change of Control
                           (the "Change of Control Loan Balance"), then the
                           Company shall make an additional payment to the
                           Executive equal to the sum of (i) the lesser of (X)
                           the difference between the Change of Control Loan
                           Balance and the Loan Payments or (Y) 20% of the sum
                           of the value of the Deferred Shares at the time of
                           such Change of Control plus the (k)(ii) Gross Up
                           Payment (the "Initial Additional Payment") plus (ii)
                           an amount (the "(k)(iii) Gross Up Payment") such
                           that, after payment by the Executive of all taxes
                           (including the excise tax under Section 4999 of the
                           Internal Revenue Code) imposed upon the (k)(iii)
                           Gross Up Payment, the Executive retains an amount of
                           the (k)(iii) Gross Up Payment equal to the excise tax
                           under Section 4999 of the Internal Revenue Code
                           imposed upon the Initial Additional Payment.

                  (iv)     The amount of the (k)(i) Gross Up Payment, the
                           (k)(ii) Gross Up Payment and the (k)(iii) Gross Up
                           Payment, each shall be calculated by the Company's
                           independent auditors at the time that such
                           calculation is necessary. The Executive shall provide
                           such information as is reasonably necessary in
                           connection with any such calculation."


                                        2
<PAGE>

4.       Except as expressly set forth in this Amendment, the Agreement remains
         unchanged and continues in full force and effect.

                  IN WITNESS WHEREOF, the undersigned have executed this
Amendment on this __ day of December, 2001, effective as of December 11, 2001.

                                             PENTON MEDIA, INC.


                                             By:
                                                --------------------------------
                                             Thomas L. Kemp
                                             Chief Executive Officer



                                             -----------------------------------
                                             Executive


                                        3