22.
Revised Editions.
If Publisher decides that a revision of the Work is desirable, it may request that Author prepare a revision not sooner than two years from the date of publication of the previous edition, and Author shall advise Publisher within 60 days of the request whether he or she will revise the Work. Author shall have a reasonable period of time in which to complete the revision, not to exceed ____ months/year(s) unless otherwise agreed. If the revision contemplated by the parties shall constitute additional materials comprising more than 25% of the text of the previous edition, Author shall receive an additional advance against royalties in an amount to be negotiated. If Author is unable or unwilling to revise the Work, Publisher may arrange to have the Work revised by a competent person and on terms subject to Author's approval, but in no event shall Author's royalties be reduced below 75% of the amount due for the previous edition for the second edition, 50% for the third, and 25% for all subsequent editions in which the Work appears.
This clause allows the publisher to ask the author to revise a work from time to time. It is only applicable to nonfiction works. If yours is a work of fiction, your publisher should readily delete this language. It is in your interest to delete this clause whenever possible and leave the terms of your work on any revised edition to future negotiations. Trade book publishers will often agree to delete the revised editions clause in its entirety. However, this is often not possible in contracts offered by other kinds of publishers. Publishers' contracts for textbooks, technical books, and other professional books often contain a provision requiring the author to make revisions for a new edition at the publisher's request, sometimes without further payment (beyond continued payment of royalties, of course). Ideally, if you are adding substantial new material in the revised edition--say, 25% or more of the text in the previous edition--then you should be entitled to an additional advance.
The typical contract states that if the author will not or cannot make the revisions, the publisher can retain the services of another author and charge that person's payment (on a flat-fee or royalty basis) against the original author's royalties. Section 22 of the Model Contract provides an example of a reasonably tailored revised edition clause, but you can further modify the clause to suit your project by negotiating for the inclusion of some or all of the following points in your contract:
If you believe that revisions will be needed to keep the book up to date and selling well, try to include a contract provision allowing you the right to revise your work within a reasonable time following first publication and requiring that if the publisher refuses to publish a revision, the agreement will terminate and the rights will revert to you. This will allow you to keep your work current and competitive.