Pathfinder Unchained is a kind of book that you could only get with a solid, mature rules system. Pathfinder may be on its initial edition but it's effectively the third edition of "d20 fantasy" and this is the kind of book you can do and do well at that point. It also helps if the game is popular enough to support this kind of supplement as I would bet that most Pathfinder campaigns will not use it, and even fewer will use anything beyond the character classes.
Unchained takes pretty much every even slightly controversial rule in Pathfinder and offers a way to change it or eliminate it. To make a comparison to a lesser-known book, it's similar to the Mutants and Masterminds "Mastermind's Manual".
- The first chapter is a reworking of 4 core classes: Barbarian, Monk, Rogue, and Summoner. I won't spend much time on these other than to say they seem solid to me and if you play one you should take a look at them. There are also sections on staggered advancement and fractional base bonuses. I've never had any players that thought the math progression in d20 was much of an issue but if you do here are a couple of ways to address it.
- Beginning with the second chapter the skill system gets a bunch of options:
- Background Skills separates out "background" skills into their own point pool. This evens out things like Profession and Craft for everyone and makes each class' skill points count towards the more adventuring-specific things like Climb or Diplomacy. I like this and I did something like it in some of my 3rd edition games years ago. It's nice to have an official option to refer people to.
- The Consolidated Skills option cuts the skill list down from 35 to 12, similar to the way D&D 4E and M&M 3E handled them. I'm a fan of the broad skill list approach in games so I like this a lot. I find players and GM's spend a lot less time debating what skill is appropriate to a given task when the broader options are used.
- Grouped Skills is an option I didn't like quite as much. It lies in between the existing granular skill system and the Consolidated option as it still uses the full list but gives bonuses for groups of similar skills. It makes characters more broadly competent but doesn't completely change up the list. I think it's a half measure but it might be easier to integrate into an existing campaign.
- Alternate Crafting and Profession rules give a different way to use them in play. The alternate crafting stuff is interesting but you need to have a player who is really interested in it to make it worth implementing. The profession section is more interesting to me as it includes a system for using one's profession to run a business, including the size of the business, profits, and how much of the character's time it takes. I don't know that it would come up a lot in my games, but it's nice to have it on the shelf if it does.
- Skill Unlocks are nifty little perks one receives in specific skills at 5/10/15/20 ranks. I'd say they are roughly equivalent to Feats but access is limited, even in this optional system, so they shouldn't break the game as presented. They's a big part of the revised Rogue class earlier in the book. I think it's a nice way to include a themed feat chain, roughly, without adding in stuff that anyone can take anytime.
- Variant Multiclassing: This is very similar to the 4th Edition D&D version of multiclassing. Instead of spending levels, a character gives up their feats at certain levels to gain features from another class. Each of the classes from the core book and the Advanced Players Guide is written up to be compatible with this approach and somewhat to my surprise I really like it. I thought one of 3E's great innovations was per-level multiclassing and I still do, but not every concept needs to take full levels in another class. Sometimes one just wants some of the flavor, and this option allows that without losing any of the benefits of your main class. I do think they are weaker than a lot of multiclass combinations, but there are still a lot of interesting possibilities here.
- After skills we get the general "Gameplay" chapter and it covers a lot of ground:
- There's a section looking at alignment and adding some new mechanics around using it in the game
- There's a section about taking alignment out of the game completely and how that affects some mechanics of the game
- Revised Action Economy: I'm not as clear on the goals for this section but the idea is to drop most of the different kinds of actions and give everyone 3 "acts" per round. This also drops multiple attacks as presented but it lets people use an act to make an attack if that's what they want to do. It's basically an action point system (see FASA Star Trek for my favorite AP system) but it feels really constrained with the 3 act (effectively 3 points) limit as all of the existing actions one can take in Pathfinder are presented in a list with a cost of 1-3 acts and various special rules or limitations applied. I think action point systems are great in general but I don't see what this one brings over the normal Pathfinder system. I don;t see the win here.
- Removing Iterative Attacks: This changes the existing system of rolling for each attack into what a lot of systems do for autofire type attacks - rolling higher = scoring multiple hits. The stated goal is to save time and I can see some of that but you are supposed to oll damage separately for each hit so I'm not sure it makes a huge difference in play. I am curious enough to consider trying this one at some point.
- Stamina and Combat Tricks: Options for fighters to do more than just swing and hit for damage. They can inflict various conditions, add temporary bonuses or penalties. There are over 20 pages of these with over 20 items on most pages so it's a very robust set of options if you choose to use it. To me it would make fighters more like 4E fighter types and their set of powers that did more than just "2d6 + Str". Another benefit I can see is differentiating between melee types even more than the system already allows. It looks interesting on paper and I'd like to see it in play some time.
- Wound Thresholds: A system that inflicts penalties as hit points drop. I like it but I'm not sure what it does to the rest of the game. A lot of players do not like "death spiral" mechanics but I don't have a huge problem with them. I tend to think of them as "warning lights" that it may be time to retreat when things start getting too hard. It does make in-combat healing more valuable than it already was, but I don't think that alone would stop me from using it. It's another item on the "we ought to try it sometime" list.
- Diseases and Poisons: Each type of disease or points has a progress track and as saves are failed or made the victim moves up or down the track and suffers from various problems. I think this would be worth it where a disease or poison was a big part of the adventure, particularly if it applied to a PC or important NPC. I don't think I would implement it just to accommodate the average rat bite.
- Chapter 4 covers Magic:
- Simplified Spellcasting: As a character progresses their lower level spells become a pool instead of something that has to be tracked every day. I like it, but I've never met a player who complained that setting their spells for the day was a chore - most of them enjoy it!
- Spell Alterations: This section presents some general options for magic as a whole: Limited Magic (weakening it overall), Wild Magic (more random!), and Active Spellcasting (use attack rolls for casting spells). Interesting but nothing that wound me up a whole lot.
- Esoteric Material Components: This really made me think of Ultima IV and it's "Reagents" for casting spells. There are some materials that enhance certain schools of magic and one universal type that can be used when casting to add in some additional effects. It's interesting but I think it would have to be a part of the campaign world to make a lot of sense. I also don't know that magic needs another option to be more powerful or have more bits to keep track of in play.
- Automatic Bonus Progression: This is one of the most interesting options in the book. The math in Pathfinder assumes characters will have certain bonus to attacks and defenses at certain levels, hence the large number of magic items that give numeric bonuses to stats, like the +1 sword, + 2 shield, or Headband of Intellect +4. This system builds those types of bonuses into the level progression (via a single table) and eliminates magical item bonuses entirely. Now a flaming sword only has the "flaming", it doesn't have to be a "+1 flaming sword". I think it would make for a very different kind of game but it's something people have discussed since D&D 3.0 rolled out and I think this is a simple and elegant approach if someone wants to explore this option/.
- Innate Item Bonuses: This is a slightly different way to do the same thing I described above but with a little more attention to items. I can see that it would probably work but I didn't like it as much as the Innate option. In short, there is a bonus associated with the type and cost of each item slot in the game and putting anything in that slot grants the character that bonus. It eliminates the +2 stat bonus item but does not automatically grant a replacement bonus unless the character slots in another item in that same slot.
- Scaling Items: This is a nice option. This changes the approach to magic items so that they grow as the character levels up. This gets rid of the whole scenario where a character has to set aside the magic sword they found at first level because it's just not strong enough at 10th. The section includes 17 pages of magic items rewritten for this approach and while I think you would want to implement it at the start of a campaign, I think it's a very nice way to make magic items take a better place in the campaign as rare and powerful items. I don't think you would need to account for magic item shops in a campaign using these rules.
- Dynamic Magic Item Creation: Makes creating a magic sword much more than a couple of rolls. Instead it's a little like a skill challenge form 4E in that there are a few steps to it and failure doesn't mean it didn't work, it just means you take more time and may have a quirk or a flaw in the item. As a DM I like it a lot, but I suspect my players would not like it as much, if only from a resource expenditure point of view. I'd say it's worth a look in any campaign.
- The final chapter is Simple Monster Creation - all 50 pages of it! Humor aside, this is a great addition to the game. It takes an approach similar to 4E of looking at the monster's role in the game, type, and level and assigning stats based on that rather than the more Hero-system-esque 3E approach of building it from the ground up just like you would a player character. If you're running your game from a computer using Hero Lab or Combat Manager then I don't think it's as much of a benefit as you have decent tools already. Similarly, if you're running an Adventure Path pretty close to the book then you may not be building many monsters anyway. However, if you are writing your own material, and especially if you're doing it on paper, this is a much better way in my opinion than the existing system.
For me, I think we're going to continue our campaign with the standard rules. Since it's Wrath of the Righteous we're already using Mythic Power and the mass combat rules from Ultimate Campaign so it's not exactly "vanilla" anyway. Once we finish it we should have seen Pathfinder at it's most over the top, all the way through 20th level. After that we may look at trying some of these out for the next campaign, and if I get some kind of side game going then they may be on the menu too.