Awesome Adam
First Post
No it's not. It's in the DMG.
Which last time I checked, was one of the three core rulebooks.
It's not a house rule. It's not something from the Dungeon Master's Guild, Unearthed Arcana, a blog, or an Enworld thread.
Like I said, it's perfectly fine if it's a rule your gaming group chooses not to use, but let's not pretend that if you don't like it, it's not an official rule, from an official source.