Truenamer

The Truenamer, from the Tome of Magic, is possibly one of the worst classes ever printed: Dungeons and Dragons or otherwise. Truenamers use a casting system that's just as horrible as they are. Having to constantly spend resources just to have a reliable chance of using your utterances successfully, coupled with the utterances being usually just bad versions of other spells that you could get at a lower level, is not exactly something that makes you excited to try playing a truenamer.

They start ok, then get worse as their utterances are still stuck copying wind wall and other lower levels spell and then they get a pretty much at-will Gate at level 19 which does NOT contain the usual extra rule that gated in creatures cannot summon other creatures, meaning that with enough turns and a good cause you can end up balls-deep in Solars and pretty much kick all the ass. The utterances often include lots of spelling errors and other omissions that make them completely different from what they were intended to do. In short, their editing and playtesting were non-existent and it shows.

However this is only the tip of the iceberg. Since their casting is tied to a skill (Truenaming) and the fact, IIRC, they get unlimited usages of utterances per day (though it gets harder with each successful uttering), with enough min-maxing you can crank your Truenaming skill high enough to never fail an Utterance EVER and thus out do a Wizard in terms of daily power (in that you don't have a daily supply but LIFETIME SUPPLY). Thus if you don't put enough into Truenaming and min/max a Truenamer it becomes a non-functional waste of paper. If you min/max the ever-living fuck out of it, you pull a Double Henderson, if not the first TRIPLE HENDERSON, since as previously mentioned, you can do everything a Wizard does but with no limits.