Andy_Langton - 3:34 pm on Mar 29, 2012 (gmt 0)

There shouldn't be a need to robots exclude redundant pages - if they have moved elsewhere, 301 them. If they don't exist any more, they will die out on there own.

Robots excluding them implies that they are present in search results - if they are, they should be good candidates for 301 redirecting.

If the desire is to remove the pages from search results, then a simple 404 (or 410) response is the quickest way to do that - robots exclusion won't speed this up.

All that said, if robots exclusion is the right choice in this situation, you could use a wildcard:

User-agent: googlebot
Disallow: *_*

Note that not all spiders support the wildcard - YMMV.