Rory and I were both 5e alpha testers. Not only that, we were among a handful of people who got alpha drafts of the Monster Manual, upon which we each submitted volumes of feedback.
I’m reading the official Monster Manual now, and I’m pleased that a lot of my suggestions were taken. In fact, about 50 monsters seem to have been changed based on my feedback.
I’d love to share all the changes with you – I’m absurdly proud of some of my tweaks – but I’m still under NDA. I’ll non-specifically break down the general categories of my comments.
About 1/4 of my suggestions were prose fixes and copy editing. These are all things that would have been found on the editing pass anyway, so they’re not really changes I can take credit for. It may have been a waste of time for me to submit them, but it doesn’t hurt to have more eyes on the document, and I’m sure WOTC doesn’t mind a little unpaid copy editing.
Another 1/4 of my edits were questions that led to rules clarifications. Again, I’m not particularly proud of these (or ashamed of them either). It’s nice to spell out how monster attack A interacts with monster attack B, but 5e tries to empower the DM to make this kind of judgment call anyway. My questions led to a little more precise language, which makes things a little easier, I guess.
I am proud of some of my fixes, though. Most of my remaining changes are gifts to the DM: things that make the world make more sense, and things that make monsters scarier or easier to run. This guy should do more bite damage, considering the size of his teeth! This guy should have a higher INT, since he’s described as a mastermind! Can we get rid of this complicated mechanic? Can this guy use a stat-block ability instead of a spell I have to look up in the PHB?
Finally, I’m most proud of my handful of changes that are gifts to the players. When it comes to players, the Monster Manual is a book that’s heavier on tricks than on treats, but I got a couple in. When you and your party are dogfighting a dragon on your exotic flying mounts, say, “Paul, you are the wind beneath my wings.”
I also had tons of suggestions that weren’t taken. Dragons have great lair actions, but I wish they had more varied normal attacks. I wish there wasn’t a Neutral Good slaver race. And I know it’s minor, but I wish that goblins didn’t have 2 HD. They’re goblins!
I submitted one more type of feedback I haven’t mentioned yet: praise. The 5e monsters have so many great, inspiring new details. I’m sure WOTC won’t mind if I’m specific about some of the things they did right:
The solar has a legendary action that permanently blinds people who presume to look upon it. This is resoundingly mythic.
The stone giant story about the “dreaming world beneath the sky” is beautiful. Stone giants were dead last in the giants-I-want-to-use race; now they’re first.
The lich has great lair actions. I particularly like the clever mechanic that recharges spells on a roll of a d6. The details of the mechanic encourage the DM to use the lich’s low-level spell slots, since they have a greater chance of recharging; this is fun because it makes for a more unpredictable fight.
Have you seen this detail in previous editions? If they don’t have specific orders, skeletons tend to perform the habitual actions they did in life: sharpen swords, patrol, etc. I love the idea of entering a skeleton-ridden town and finding some skeletons out in the fields behind skeletal oxen, some raising empty tankards in the inn, and some plucking at looms empty of thread.