When the first book of Horrifically Overpowered feats was released on April 1st, 2012, we expected to hear a lot of cries of "What were you thinking?!" Instead we mostly heard "When will you release more?!"
The obvious answers should have been either "Never!" or "Not until we can sneak them in on April 1st, 2013!" But to some extent, that's cheating. Either we want to release more Horrifically Overpowered feats, or we don't—hiding behind a Fool's Day would show a lack of conviction on our part. And, it turns out, we do want to release more. But if we're going to do that, and we're not going to claim it's a joke, some defense of the idea is in order.
Horrifically Overpowered feats, as the name might suggest, are not balanced. They are, in fact, imbalanced in three ways. First, each one represents an uptick in power larger than a typical feat (and in most cases, larger than the most powerful feats). Second, each one has the potential for being combined with class features, spells, tactics, and other feats to create an even-stronger effect than normal, causing them to skew how big a boost in power depending on the circumstances. Third, conceptually many of them bend the logic of the core rules, allowing warriors to cast spells, spellcasters to become weaponmasters, and well-designed characters to be much, much more effective than characters that have not been optimized.
Given the long list of sins placed at Horrifically Overpowered Feat's, er, feet, it may sound as if these rules are unusable. That's not strictly speaking true. Each feat is designed to give all the rules needed to use it in a campaign, and to be consistent and logical within the frame of reference of being Horrifically Overpowered. It's just that the feats themselves are intentionally too much to reasonably be added to a typical game.
So, why produce more of them?
The fact of the matter is that no two gaming groups are the same, and no two campaigns have exactly the same needs. After The Genius Guide to Horrifically Overpowered Feats came out, numerous customers gushed about the ways they had found to use these feats in their games. These ranged from only giving them to monsters, to using them to allow 3-man adventuring parties to survive encounters designed for 4 heroes, and even as special temporary divine blessings or for powers of artifacts. We didn't want to tell our customers they were doing it wrong, and since there seems to be a real enjoyment of such things, we began work on the second volume in what is scheduled to eventually be a 32-part line.
(Okay, probably not. But if the sales are good enough...)
However, we aren't kidding when we say these things do not meet the normal rules of good feat design. Such feats can badly unbalance a game, and shouldn't be used by anyone, at any time, without a really good reason. GMs who feel they know what they are doing are, of course, welcomed to find interesting ways to add horrifically overpowered feats to a game (we made some suggestions in The Genius Guide to Horrifically Overpowered Feats).
But we warned you.