Shape Changing Rules
Part One
Shapechanging magic (polymorph, polymorph any object, shapechange) is completely frelled. The idea of changing shape is such a strong one in fantasy literature, but we've yet to see a version of polymorph that isn't horribly abusable. Every new revision just changes the dumb tricks players can use. And there are a lot of reasons for this, I think.
1.) Monsters aren't designed with players in mind. Most of them are given abilities that, in the hands of PCs, are insanely game-breaking. There's no standardization for monster abilites, no basis for how to build them so that they won't become abusable. This is the basis for ECL, but unfortunately ECL doesn't help when you can shapechangeinto that creature anyway.
2.) What abilities are granted by polymorph is confusing because not all monster authors were consistent in putting certain abilities in the "Special Attack" line and others in the "Special Qualities" line. Further, the defining abilities of a creature may actually be SQ's; with polymorph as worded, you do not get Scent if you change into a wolf, or you do not gain Low-light Vision if you change into an owl. That's counterintuitive.
3.) Polymorph currently makes your physical scores irrelevent. This is mostly a druid issue; after 5th level, a druid can take Natural Spell and spend all of his/her time in wild shape, making her rolled physical scores meaningless. A 5 Dexterity? No problem, I'll just stay in bear form all day. Blech.
4.) The 3.5 versions grant creature type. There are 101 Stupid Player Tricks to abuse this situation, all of which are ridiculous but technically possible. A druid can cast Awaken on himself when in animal form, just to point out the stupidest one. There are also situations where a character can polymorph to a creature type that is immune to polymorph. So what the hell happens then? No, this was a bad idea that needs to be rolled back.
5.) On a similar note, 3.5 shapechange grants Supernatural abilities. The number of abusive or even incomprehensible situations this cause will boggle your mind if you think about it too hard. Just as a taste, you can turn into a Choker and regain the 3.0 haste ability of an extra standard action per turn, or (in an example of a really badly written entry), you can turn into a Balor and gain a Vorpal Sword as a supernatural ability. And don't get me started on Barghests and Phoenixes.
6.) Every time someone puts out a new monster book, the opportunity for abuse from those last two points rises exponentially, as new authors put out monsters that don't follow the rules precisely or simply don't consider the ramifications of PCs turning into their monsters.
7.) One good thing on the surface for the 3.5 revisions: No more permanent duration for one version of polymorph, which used to make it worthwhile to turn all your party's fighters into Firbolgs, permanently. BUT, they really just delayed it a few levels, because currently polymorph any object can turn a human into a Firbolg permanently (since a giant might be considered "related" to a human, which makes a total Duration Factor of 9). What's more, PAO will actually give your fighter friend a BOOST to his Intelligence, for free, when you permanently polymorph him into a Firbolg. Who thought THAT was a good idea??
8.) All the shapechanging magic gives a +10 unnamed bonus to Disguise, which stacks with itself. So you can polymorph yourself into a human, cast alter self and disguise self and end up with a +30 bonus to Disguise. Ummmm…no thanks.
9.) On a related note, alter self is abusable in combo with polymorph by using the latter spell to take the form of a creature with ultra-high physical stats, and then casting the former to regain your normal appearance. So you can walk around all day with the stats and abilities of a Firbolg or troll but still look like you. No, these effects clearly need to replace one another, not stack.
Building the Foundation:
1.) There needs to still be a 4th level and a 9th level version of shapechanging spell, whatever form it takes. Further, every class or major monster with shapechanging abilities needs to work with whatever I come up with.
2.) Shapechanging is just that: The change of the shape. I want to move away from the idea that you actually become whatever creature whose shape you mimic and towards the idea that it is still you, just reconfigured. That means certain abilities will stay unaltered, and that ability scores will be based on your actual ability scores.
3.) There need to be limits on certain features to prevent unforeseen abuse when some author writes a 1 Hit Dice creature with a +34 natural armor class bonus. Again, move away from the idea of being able to have it when you polymorph just because it's written in the monster description.
4.) I don't want poison or other "milkable" monster traits to function. If the poison spell is 4th level, it is hard to justify a spell that is the same level but lets you poison someone again and again, and possibly with a nastier poison.
The Big Reveal:
This is going to be in two parts. This week, the basics of my new plan: the Polymorphed Creature template and the spells that grant it. In Part 2, I deal with turning creatures into inanimate objects, offensive polymorphing, wild shape, alter self, and monsters.
This article has been revised from its original form; all revisions are listed in this color.