From IFWiki

The term textdump refers to any large section of text uninterrupted by a prompt at which the player can enter input; it has strong negative connotations. It is also occasionally applied to other media, in places where the audience doesn't expect to read much - for instance, a lengthy piece of expostulatory text at the start of a movie. (See also Cutscene). The related term infodump is, straightforwardly, used for when a work throws an immense amount of information at a player all at once, rather than slowly revealing it over time.

Reasons Not to Textdump

  • The attention span expectations for computer games are generally lower than for novels or other pure-text media; this might affect IF to a lesser degree, but it remains a factor.
  • Important information is more likely to be missed or forgotten if contained in a single massive textdump. Reveal backstory or important knowledge to your audience gradually, or they're unlikely to care much about it.
  • Textdumps make a much higher demand on prose quality. An audience indifferent (or even hostile) to your prose might tolerate it in the course of normal gameplay, but if expected to wade through a huge chunk of it they'll probably just skim-read or quit.