Because "48" isn't a letter and F was already taken...
The 48 Laws of Power, by Robert Greene, goes into far more depth than Machiavelli's The Prince (though you should read that) and Sun Tzu's Art of War (read that too.) In some ways, I suspect 48 might be more laws than is necessary -- some of them overlap each other noticeably. And some do seem difficult to reconcile to each other, if not downright contradictory.
That's not as much a problem as one might think, as the idea that nobody can observe all these laws perfectly and therefore be the perfect leader (dictator, con man, etc.)... is rather reassuring, actually.
On the whole, though, the weight of so many examples is persuasive. While I recommend this book for anybody who wants their characters to be successful leaders, I do NOT recommend plowing through the whole book all at once. Doing that contributed noticeably to my jaded, pessimistic and manipulative side.
On the other hand, it did make me a lot more comfortable with letting my kings, empresses, and rebel leaders pull the gloves off and get stuff done. When Maggie McBride, my rebel leader, had to address the fact that one of her staunchest supporters had screwed up, gone behind her back to try to fix it and made things worse... I checked this book before writing the confrontation. It confirmed that she had to take him down a peg and challenge him to make it right, while making it clear she trusted he would.
Leaders are difficult to write, when you're a shy person. This book has helped me a lot.