Chapter 3 takes all the building blocks from Chapter 2 and makes actual superpowers. Similar to the Effects chapter, each Powers has a listed point cost, description, and lists of appropriate modifiers. The entries also include a breakdown of which effects and modifiers make up the power in question. Furthermore, each power lists a number of associated effects, powers that aren't linked to the main power (as an Alternate Power would be) but often are linked due to descriptors. For example, Jean Grey's Flight and Telekinesis are two separate powers, as she can use them at the same time, but both spring from the same telekinetic source.
Pretty much every power that's been shown in comics has a write-up here, from Bouncing to Magnetic Control to that most ridiculous feat of the Silver Age Superman, Super-Ventriloquism.
The book finishes up with two Appendices. The first has notes from the designers detailing some of the rationales behind some of the design choices, as well as some suggestions for how to handle problems that might come up due to super powers. The second Appendix has a full list of all the Effects and Powers from Chapters 2 & 3, providing a handy reference.
The art, for the most part, is awesome. Of all the M&M products I've reviewed thus far, this one wins hands down in the art department.
Overall, is Ultimate Power necessary to run an M&m game? However, this book is incredibly useful for a game system that has such a large focus on superpowers. Not absolutely necessary, but strongly suggested.
