Cheiromancer
2013-08-06, 03:17 PM
I find polymorph highly problematic. First, it is a real chore to figure out what a new form gets you. Second, many of the forms seem highly abusive. The result is that polymorph (and its little brother, alter self) figure prominently in ban/nerf lists.
So here is an idea based on the planar exchange line of spells in the Spell Compendium (p.159). Basically a cleric replaces himself with a conjured creature, gaining full control over its actions - except the conjured creature cannot summon other creatures. The list of available creatures is extremely limited, but there are spell-like and supernatural abilities available. (You can get a bone devil with the 6th level spell version!)
So I was thinking that when you polymorph you are replaced with another creature that you control. You play the new form right out of the book, not worrying about exactly which abilities are gained or lost. Here's a draft of the spell text (compare with polymorph (http://www.d20srd.org/srd/spells/polymorph.htm) and alter self (http://www.d20srd.org/srd/spells/alterSelf.htm)).
edit: I've made multiple versions of the spells. The alter self analogue is automorph, and the basic polymorph spell is polymorph I. A lot of it is boiler-plate language that could be written elsewhere (as PHB II does for the polymorph subschool).
Automorph
Transmutation
Level: Sor/Wiz 2
Components: V, S
Casting Time: 1 standard action
Range: Personal
Target: You
Duration: 10 min./level (D)
You assume the form of another creature. The new form must be within one size category of your normal size and of the animal or humanoid type, and is chosen when you prepare the spell. If you do not prepare spells, choose a form when you regain spells; this choice counts for all your daily castings of this spell. The HD of the assumed form cannot exceed your caster level, to a maximum of 10 HD at 10th level. Furthermore, the CR of an assumed form cannot exceed one half your caster level, to a maximum of CR 5 at 10th level.
The spell otherwise functions as polymorph I. If the spell ends due to the death of the assumed form, you take 2d6 damage and are dazed for one round.
Dimorph I
Transmutation
Level: Sor/Wiz 3
Components: V, S, M
Casting Time: 1 standard action
Range: Personal
Target: You
Duration: 1 hour/level (D)
You may alternate between two different forms, as if by the polymorph I spell. One form may be your natural form and the other form a humanoid or animal, or you may choose two animal forms, two humanoid forms, or both a humanoid and an animal form. The forms are chosen when you prepare the spell. If you do not prepare spells, choose the forms when you regain spells; this choice counts for all your daily castings of this spell.
You have access to your class abilities only while you are in your natural form. Damage sustained in one form does not go away if another form is assumed; track the damage and conditions affecting each form separately. Changing between forms is a standard action that provokes an attack of opportunity.
You gain low light vision and the scent ability for the duration of the spell. While you are in an assumed form you also gain DR 5/silver. If the spell ends due to the death of an assumed form, you take 3d6 damage and are dazed for one round.
Material Component: hair from a shapeshifter
Polymorph I
Transmutation
Level: Sor/Wiz 4
Components: V, S
Casting Time: 1 standard action
Range: Touch
Target: Willing creature touched
Duration: 1 min./level (D)
Saving Throw: None
Spell Resistance: No
You replace the body of a willing subject with that of another creature, while keeping the subject's mind intact. You cannot cause a subject to assume an incorporeal or gaseous form, but otherwise the assumed form may be any of the following types: animal, dragon, fey, giant, humanoid, magical beast or monstrous humanoid.
The assumed form is chosen when you prepare the spell. If you do not prepare spells, choose a form from one of the available types when you regain spells; this choice counts for all your daily castings of this spell. The HD of the assumed form cannot exceed your caster level (or the subject’s HD, whichever is lower), to a maximum of 15 HD at 15th level. Furthermore, the CR of the assumed form cannot exceed two thirds your caster level, to a maximum of CR 10 at 15th level.
The assumed form has the normal statistics for a basic creature of its kind, without hit dice advancement or templates. It is effectively a separate entity from the subject's natural form, with its own hit points, BAB and saving throws. If the form of a humanoid is chosen, you may include levels of warrior as long as the HD and CR are within the spell limits. These levels do not provide skill or feats; rather, a humanoid form has the subject's skills and feats, in addition to any racial bonus feats. Note that some of these feats may be unusable, either because they modify inaccessible class features or for some other reason.
The assumed form is not affected by spells that were previously cast on the subject, nor is the subject's natural form affected by spells or effects that target the assumed form. None of the subject's own abilities are available in the assumed form, not even feats or skills. The subject can, however, understand languages normally, and can speak them if the description of the assumed form indicates that it has a spoken language.
The subject gains all the abilities of the assumed form, except as follows. First, any assumed abilities that are usable a limited number of times are reduced to half the normal frequency, unless the ability is no more powerful than a second level spell. For example, someone in the form of an ogre mage can use charm person and sleep once each, but not cone of cold. Second, the subject does not gain class abilities (such as "cast spells as a 10th level sorcerer" or "use psionics as a 5th level wilder"). Finally, the assumed form cannot change shape or use the alternate form special ability, nor can it summon other creatures, nor use abilities related to spawning or reproduction.
You can freely designate the assumed form’s minor physical qualities (such as hair color, hair texture, and skin color) within the normal ranges for a creature of that kind. The new form’s significant physical qualities (such as height, weight, and gender) are also under your control, but they must fall within the norms for the new form’s kind. The subject is effectively disguised as an average member of the new form’s race. If you use this spell to create a disguise (whether for yourself or another), you get a +10 bonus on your Disguise check.
If the assumed form's size is different from the subject's normal size, its new space must share as much of the original form's space as possible, squeezing into the available space (see PHB 148) if necessary. If insufficient space exists for the assumed form, the spell fails.
When the change occurs, the subject drops whatever it is holding. In addition the subject's equipment, if any, disappears along with the old form and becomes nonfunctional. When the subject reverts to its previous form, these objects reappear in the same location on its body they previously occupied and regain functionality. Any new items worn in the assumed form fall off and land at the subject's feet. Any part of the body that is separated from the whole vanishes when the spell ends.
Incorporeal or gaseous creatures cannot be polymorphed, and a creature with the shapechanger subtype can revert to its natural form as a standard action. You can dismiss the spell by touch with a standard action. If the assumed form is slain the spell ends, causing the subject to take 4d6 damage and be dazed for 1 round.
Dimorph II
Transmutation
Level: Sor/Wiz 5
Components: V, S, M
Casting Time: 1 standard action
Range: Personal
Target: You
Duration: 1 hour/level (D)
As dimorph I, except the alternate form(s) may be of the following types: animal, dragon, fey, giant, humanoid, magical beast or monstrous humanoid. If the spell ends due to the death of an assumed form, you take 5d6 damage and are dazed for one round.
Polymorph II
Transmutation
Level: Sor/Wiz 6
Components: V, S
Casting Time: 1 standard action
Range: Touch
Target: Willing creature touched
Duration: 1 min./level (D)
Saving Throw: None
Spell Resistance: No
You cause a willing subject to assume the form of an aberration, ooze, plant or vermin. The HD of the assumed form cannot exceed your caster level (or the subject’s HD, whichever is lower), to a maximum of 20 HD at 20th level. Furthermore, the CR of the assumed form cannot exceed two thirds your caster level, to a maximum of CR 13 at 20th level.
The spell otherwise functions as polymorph I. If the spell ends due to the death of the assumed form, the subject takes 6d6 damage and is dazed for one round.
Polymorph III
Transmutation
Level: Sor/Wiz 7
Components: V, S
Casting Time: 1 standard action
Range: Touch
Target: Willing creature touched
Duration: 1 min./level (D)
Saving Throw: None
Spell Resistance: No
You cause a willing subject to assume the form of an aberration or outsider. The HD of the assumed form cannot exceed your caster level (or the subject’s HD, whichever is lower), to a maximum of 20 HD at 20th level. Furthermore, the CR of the assumed form cannot exceed two thirds your caster level, to a maximum of CR 13 at 20th level.
The spell otherwise functions as polymorph I. If the spell ends due to the death of the assumed form, the subject takes 7d6 damage and is dazed for one round.
Polymorph IV
Transmutation
Level: Sor/Wiz 8
Components: V, S
Casting Time: 1 standard action
Range: Touch
Target: Willing creature touched
Duration: 1 min./level (D)
Saving Throw: None
Spell Resistance: No
You cause a willing subject to assume the form of an undead. You may select any corporeal form of undead, subject to the HD and CR limits given below. You may even choose an undead form that is the result of a template, but the base creature must be humanoid. The base creature may have levels of warrior as long as the HD and CR are within the spell limits. These class levels do not provide skills or feats; rather, the undead warrior has the skills and feats of the subject in addition to any bonus feats from the base race and template. Note that some of the subject's feats may be unusable while in undead form, either because they modify inaccessible class features or for some other reason.
The subject does not benefit from abilities that provide alternatives to destruction, such as a lich's phylactery or a vampire's ability to assume gaseous form upon being reduced to 0 hit points. The HD of the assumed form cannot exceed your caster level (or the subject’s HD, whichever is lower), to a maximum of 25 HD at 25th level. Furthermore, the CR of the assumed form cannot exceed two thirds your caster level, to a maximum of CR 16 at 25th level.
The spell otherwise functions as polymorph I. If the spell ends due to the destruction of the assumed form, the subject takes 8d6 damage and is dazed for one round.
Polymorph V
Transmutation
Level: Sor/Wiz 9
Components: V, S
Casting Time: 1 standard action
Range: Touch
Target: Willing creature touched
Duration: 1 min./level (D)
Saving Throw: None
Spell Resistance: No
You cause a willing subject to assume the form of a construct. The HD of the assumed form cannot exceed your caster level (or the subject’s HD, whichever is lower), to a maximum of 25 HD at 25th level. Furthermore, the CR of the assumed form cannot exceed two thirds your caster level, to a maximum of CR 16 at 25th level.
The spell otherwise functions as polymorph I. If the spell ends due to the destruction of the assumed form, the subject takes 9d6 damage and is dazed for one round.
Shapechange
Transmutation
Level: Sor/Wiz 9
Components: V, S, F
Casting Time: 1 standard action
Range: Personal
Target: You
Duration: 10 min./level (D)
This spell functions like polymorph I except as stated here. You may select any eligible form when you cast the spell and may change form once per round thereafter as a standard action. An assumed form may be any of the following types: aberration, animal, dragon, fey, giant, humanoid, magical beast, monstrous humanoid, ooze, plant or vermin. You may also return to your normal form, which allows you to use your class abilities and equipment.
The HD of an assumed form cannot exceed your caster level (or the subject’s HD, whichever is lower), to a maximum of 25 HD at 25th level. Furthermore, the CR of an assumed form cannot exceed two thirds your caster level, to a maximum of CR 16 at 25th level.
The form you assume when you cast the spell shares your hit points. Your hit points change according to the damage and/or healing an assumed form receives. You perish if an assumed form dies or is destroyed, even if your true form would be immune to the damage or effect that proved fatal. Your death or destruction does not automatically end the spell.
Focus: A jade circlet worth no less than 1,500 gp, which you must place on your head when casting the spell. (The focus melds into your new form when you change shape.)
Note that creatures do not get a special ability to polymorph into creatures of their own type: in particular, outsiders do not get to use the 4th level polymorph to turn into other outsiders. And while supernatural and spell-like abilities are available, the best of them are usable only 1/day (or less), and so are inaccessible. I would think that any other ability could already be acquired via charm monster and the like, and so if they are acquired with this spell it wouldn't be a problem. And you can't use your own feats or abilities; you are playing the monster out of the monster manual. Finally, the double limitation on hit dice and CR should keep things sane, especially with ability frequency cut in half. (edit: some broken abilities can be accessed with polymorph V. Players and DM's ought to have an understanding about such things.)
The planar exchange spells are Conjuration (calling) but I'd like to retain this as Transmutation. Although mechanically you play another creature right out of the monster manual, really you have been transformed so completely that nothing except your mind is retained from your previous form.
So... how can this spell be abused? If there are abuses, can it be further tweaked to correct them? Any wording or mechanics that need to be reworked or tweaked? Any help would be appreciated.
major edit history
edit: clarified that the subject's own abilities are not retained, tinkered slightly with wording and ordering of material.
edit2: no class levels. But as for templates- why not? Make each add an additional +1 in addition to the normal cost, so as to ensure under-costed templates aren't used. Maybe in the next edit...
edit3: tweaked wording again. Cannot gain the alternate form or change shape special abilities. Mostly because they are the sort of book-keeping nightmare that this is intended to address.
edit4: dropped aberration, ooze, plant, and vermin from possible forms. They could go into a level 5 version. Increased damage from 2d6 to 4d6 if the spell ends due to death of the assumed form; the subject is also dazed. Can dismiss the spell as a mental action. Added extra text from alter self and the polymorph spell description. Other tweaks of wording.
edit 6: Added a lower level version (which would replace alter self) and the promised 5th level version with the wacky forms. Humanoid forms are reserved for the 3rd level version.
edit 7:Added some wording about size changes.
edit 8: still worried about too much tactical flexibility. Made it so the form is chosen in the morning when spells is prepared or regained.
edit 9: Dropped the requirement that the subject be living. Adjusted levels upwards. Also added the versions for outsiders, corporeal undead and constructs.
edit 10: Added a material component. Any form that the DM wishes to control can be given an expensive (or even unpurchasable) component so that Eschew Materials won't work.
edit 11: I didn't feel right about the material component. It is better for players and DM's to know what is acceptable at the table. The following was removed from the spell description: "Material Component: An empty cocoon. Rare or powerful forms may in addition require a tiny fragment of the creature whose form will be assumed; these are usually expensive and hard to find. Check with your DM."
edit 12: I had to modify polymorph IV to allow templated undead. How else could you turn into a lich or vampire?
edit 13: The automorph variant needs to be able to include class levels for humanoids.
edit 14: Moved some spells down a level, and added a higher level version of dimorph. I think the limited flexibility and suppression of class abilities is enough. There might need to be a limitation on high level at-will abilities, but given the CR limits they shouldn't be serious. Except for the adamantine horror!
So here is an idea based on the planar exchange line of spells in the Spell Compendium (p.159). Basically a cleric replaces himself with a conjured creature, gaining full control over its actions - except the conjured creature cannot summon other creatures. The list of available creatures is extremely limited, but there are spell-like and supernatural abilities available. (You can get a bone devil with the 6th level spell version!)
So I was thinking that when you polymorph you are replaced with another creature that you control. You play the new form right out of the book, not worrying about exactly which abilities are gained or lost. Here's a draft of the spell text (compare with polymorph (http://www.d20srd.org/srd/spells/polymorph.htm) and alter self (http://www.d20srd.org/srd/spells/alterSelf.htm)).
edit: I've made multiple versions of the spells. The alter self analogue is automorph, and the basic polymorph spell is polymorph I. A lot of it is boiler-plate language that could be written elsewhere (as PHB II does for the polymorph subschool).
Automorph
Transmutation
Level: Sor/Wiz 2
Components: V, S
Casting Time: 1 standard action
Range: Personal
Target: You
Duration: 10 min./level (D)
You assume the form of another creature. The new form must be within one size category of your normal size and of the animal or humanoid type, and is chosen when you prepare the spell. If you do not prepare spells, choose a form when you regain spells; this choice counts for all your daily castings of this spell. The HD of the assumed form cannot exceed your caster level, to a maximum of 10 HD at 10th level. Furthermore, the CR of an assumed form cannot exceed one half your caster level, to a maximum of CR 5 at 10th level.
The spell otherwise functions as polymorph I. If the spell ends due to the death of the assumed form, you take 2d6 damage and are dazed for one round.
Dimorph I
Transmutation
Level: Sor/Wiz 3
Components: V, S, M
Casting Time: 1 standard action
Range: Personal
Target: You
Duration: 1 hour/level (D)
You may alternate between two different forms, as if by the polymorph I spell. One form may be your natural form and the other form a humanoid or animal, or you may choose two animal forms, two humanoid forms, or both a humanoid and an animal form. The forms are chosen when you prepare the spell. If you do not prepare spells, choose the forms when you regain spells; this choice counts for all your daily castings of this spell.
You have access to your class abilities only while you are in your natural form. Damage sustained in one form does not go away if another form is assumed; track the damage and conditions affecting each form separately. Changing between forms is a standard action that provokes an attack of opportunity.
You gain low light vision and the scent ability for the duration of the spell. While you are in an assumed form you also gain DR 5/silver. If the spell ends due to the death of an assumed form, you take 3d6 damage and are dazed for one round.
Material Component: hair from a shapeshifter
Polymorph I
Transmutation
Level: Sor/Wiz 4
Components: V, S
Casting Time: 1 standard action
Range: Touch
Target: Willing creature touched
Duration: 1 min./level (D)
Saving Throw: None
Spell Resistance: No
You replace the body of a willing subject with that of another creature, while keeping the subject's mind intact. You cannot cause a subject to assume an incorporeal or gaseous form, but otherwise the assumed form may be any of the following types: animal, dragon, fey, giant, humanoid, magical beast or monstrous humanoid.
The assumed form is chosen when you prepare the spell. If you do not prepare spells, choose a form from one of the available types when you regain spells; this choice counts for all your daily castings of this spell. The HD of the assumed form cannot exceed your caster level (or the subject’s HD, whichever is lower), to a maximum of 15 HD at 15th level. Furthermore, the CR of the assumed form cannot exceed two thirds your caster level, to a maximum of CR 10 at 15th level.
The assumed form has the normal statistics for a basic creature of its kind, without hit dice advancement or templates. It is effectively a separate entity from the subject's natural form, with its own hit points, BAB and saving throws. If the form of a humanoid is chosen, you may include levels of warrior as long as the HD and CR are within the spell limits. These levels do not provide skill or feats; rather, a humanoid form has the subject's skills and feats, in addition to any racial bonus feats. Note that some of these feats may be unusable, either because they modify inaccessible class features or for some other reason.
The assumed form is not affected by spells that were previously cast on the subject, nor is the subject's natural form affected by spells or effects that target the assumed form. None of the subject's own abilities are available in the assumed form, not even feats or skills. The subject can, however, understand languages normally, and can speak them if the description of the assumed form indicates that it has a spoken language.
The subject gains all the abilities of the assumed form, except as follows. First, any assumed abilities that are usable a limited number of times are reduced to half the normal frequency, unless the ability is no more powerful than a second level spell. For example, someone in the form of an ogre mage can use charm person and sleep once each, but not cone of cold. Second, the subject does not gain class abilities (such as "cast spells as a 10th level sorcerer" or "use psionics as a 5th level wilder"). Finally, the assumed form cannot change shape or use the alternate form special ability, nor can it summon other creatures, nor use abilities related to spawning or reproduction.
You can freely designate the assumed form’s minor physical qualities (such as hair color, hair texture, and skin color) within the normal ranges for a creature of that kind. The new form’s significant physical qualities (such as height, weight, and gender) are also under your control, but they must fall within the norms for the new form’s kind. The subject is effectively disguised as an average member of the new form’s race. If you use this spell to create a disguise (whether for yourself or another), you get a +10 bonus on your Disguise check.
If the assumed form's size is different from the subject's normal size, its new space must share as much of the original form's space as possible, squeezing into the available space (see PHB 148) if necessary. If insufficient space exists for the assumed form, the spell fails.
When the change occurs, the subject drops whatever it is holding. In addition the subject's equipment, if any, disappears along with the old form and becomes nonfunctional. When the subject reverts to its previous form, these objects reappear in the same location on its body they previously occupied and regain functionality. Any new items worn in the assumed form fall off and land at the subject's feet. Any part of the body that is separated from the whole vanishes when the spell ends.
Incorporeal or gaseous creatures cannot be polymorphed, and a creature with the shapechanger subtype can revert to its natural form as a standard action. You can dismiss the spell by touch with a standard action. If the assumed form is slain the spell ends, causing the subject to take 4d6 damage and be dazed for 1 round.
Dimorph II
Transmutation
Level: Sor/Wiz 5
Components: V, S, M
Casting Time: 1 standard action
Range: Personal
Target: You
Duration: 1 hour/level (D)
As dimorph I, except the alternate form(s) may be of the following types: animal, dragon, fey, giant, humanoid, magical beast or monstrous humanoid. If the spell ends due to the death of an assumed form, you take 5d6 damage and are dazed for one round.
Polymorph II
Transmutation
Level: Sor/Wiz 6
Components: V, S
Casting Time: 1 standard action
Range: Touch
Target: Willing creature touched
Duration: 1 min./level (D)
Saving Throw: None
Spell Resistance: No
You cause a willing subject to assume the form of an aberration, ooze, plant or vermin. The HD of the assumed form cannot exceed your caster level (or the subject’s HD, whichever is lower), to a maximum of 20 HD at 20th level. Furthermore, the CR of the assumed form cannot exceed two thirds your caster level, to a maximum of CR 13 at 20th level.
The spell otherwise functions as polymorph I. If the spell ends due to the death of the assumed form, the subject takes 6d6 damage and is dazed for one round.
Polymorph III
Transmutation
Level: Sor/Wiz 7
Components: V, S
Casting Time: 1 standard action
Range: Touch
Target: Willing creature touched
Duration: 1 min./level (D)
Saving Throw: None
Spell Resistance: No
You cause a willing subject to assume the form of an aberration or outsider. The HD of the assumed form cannot exceed your caster level (or the subject’s HD, whichever is lower), to a maximum of 20 HD at 20th level. Furthermore, the CR of the assumed form cannot exceed two thirds your caster level, to a maximum of CR 13 at 20th level.
The spell otherwise functions as polymorph I. If the spell ends due to the death of the assumed form, the subject takes 7d6 damage and is dazed for one round.
Polymorph IV
Transmutation
Level: Sor/Wiz 8
Components: V, S
Casting Time: 1 standard action
Range: Touch
Target: Willing creature touched
Duration: 1 min./level (D)
Saving Throw: None
Spell Resistance: No
You cause a willing subject to assume the form of an undead. You may select any corporeal form of undead, subject to the HD and CR limits given below. You may even choose an undead form that is the result of a template, but the base creature must be humanoid. The base creature may have levels of warrior as long as the HD and CR are within the spell limits. These class levels do not provide skills or feats; rather, the undead warrior has the skills and feats of the subject in addition to any bonus feats from the base race and template. Note that some of the subject's feats may be unusable while in undead form, either because they modify inaccessible class features or for some other reason.
The subject does not benefit from abilities that provide alternatives to destruction, such as a lich's phylactery or a vampire's ability to assume gaseous form upon being reduced to 0 hit points. The HD of the assumed form cannot exceed your caster level (or the subject’s HD, whichever is lower), to a maximum of 25 HD at 25th level. Furthermore, the CR of the assumed form cannot exceed two thirds your caster level, to a maximum of CR 16 at 25th level.
The spell otherwise functions as polymorph I. If the spell ends due to the destruction of the assumed form, the subject takes 8d6 damage and is dazed for one round.
Polymorph V
Transmutation
Level: Sor/Wiz 9
Components: V, S
Casting Time: 1 standard action
Range: Touch
Target: Willing creature touched
Duration: 1 min./level (D)
Saving Throw: None
Spell Resistance: No
You cause a willing subject to assume the form of a construct. The HD of the assumed form cannot exceed your caster level (or the subject’s HD, whichever is lower), to a maximum of 25 HD at 25th level. Furthermore, the CR of the assumed form cannot exceed two thirds your caster level, to a maximum of CR 16 at 25th level.
The spell otherwise functions as polymorph I. If the spell ends due to the destruction of the assumed form, the subject takes 9d6 damage and is dazed for one round.
Shapechange
Transmutation
Level: Sor/Wiz 9
Components: V, S, F
Casting Time: 1 standard action
Range: Personal
Target: You
Duration: 10 min./level (D)
This spell functions like polymorph I except as stated here. You may select any eligible form when you cast the spell and may change form once per round thereafter as a standard action. An assumed form may be any of the following types: aberration, animal, dragon, fey, giant, humanoid, magical beast, monstrous humanoid, ooze, plant or vermin. You may also return to your normal form, which allows you to use your class abilities and equipment.
The HD of an assumed form cannot exceed your caster level (or the subject’s HD, whichever is lower), to a maximum of 25 HD at 25th level. Furthermore, the CR of an assumed form cannot exceed two thirds your caster level, to a maximum of CR 16 at 25th level.
The form you assume when you cast the spell shares your hit points. Your hit points change according to the damage and/or healing an assumed form receives. You perish if an assumed form dies or is destroyed, even if your true form would be immune to the damage or effect that proved fatal. Your death or destruction does not automatically end the spell.
Focus: A jade circlet worth no less than 1,500 gp, which you must place on your head when casting the spell. (The focus melds into your new form when you change shape.)
Note that creatures do not get a special ability to polymorph into creatures of their own type: in particular, outsiders do not get to use the 4th level polymorph to turn into other outsiders. And while supernatural and spell-like abilities are available, the best of them are usable only 1/day (or less), and so are inaccessible. I would think that any other ability could already be acquired via charm monster and the like, and so if they are acquired with this spell it wouldn't be a problem. And you can't use your own feats or abilities; you are playing the monster out of the monster manual. Finally, the double limitation on hit dice and CR should keep things sane, especially with ability frequency cut in half. (edit: some broken abilities can be accessed with polymorph V. Players and DM's ought to have an understanding about such things.)
The planar exchange spells are Conjuration (calling) but I'd like to retain this as Transmutation. Although mechanically you play another creature right out of the monster manual, really you have been transformed so completely that nothing except your mind is retained from your previous form.
So... how can this spell be abused? If there are abuses, can it be further tweaked to correct them? Any wording or mechanics that need to be reworked or tweaked? Any help would be appreciated.
major edit history
edit: clarified that the subject's own abilities are not retained, tinkered slightly with wording and ordering of material.
edit2: no class levels. But as for templates- why not? Make each add an additional +1 in addition to the normal cost, so as to ensure under-costed templates aren't used. Maybe in the next edit...
edit3: tweaked wording again. Cannot gain the alternate form or change shape special abilities. Mostly because they are the sort of book-keeping nightmare that this is intended to address.
edit4: dropped aberration, ooze, plant, and vermin from possible forms. They could go into a level 5 version. Increased damage from 2d6 to 4d6 if the spell ends due to death of the assumed form; the subject is also dazed. Can dismiss the spell as a mental action. Added extra text from alter self and the polymorph spell description. Other tweaks of wording.
edit 6: Added a lower level version (which would replace alter self) and the promised 5th level version with the wacky forms. Humanoid forms are reserved for the 3rd level version.
edit 7:Added some wording about size changes.
edit 8: still worried about too much tactical flexibility. Made it so the form is chosen in the morning when spells is prepared or regained.
edit 9: Dropped the requirement that the subject be living. Adjusted levels upwards. Also added the versions for outsiders, corporeal undead and constructs.
edit 10: Added a material component. Any form that the DM wishes to control can be given an expensive (or even unpurchasable) component so that Eschew Materials won't work.
edit 11: I didn't feel right about the material component. It is better for players and DM's to know what is acceptable at the table. The following was removed from the spell description: "Material Component: An empty cocoon. Rare or powerful forms may in addition require a tiny fragment of the creature whose form will be assumed; these are usually expensive and hard to find. Check with your DM."
edit 12: I had to modify polymorph IV to allow templated undead. How else could you turn into a lich or vampire?
edit 13: The automorph variant needs to be able to include class levels for humanoids.
edit 14: Moved some spells down a level, and added a higher level version of dimorph. I think the limited flexibility and suppression of class abilities is enough. There might need to be a limitation on high level at-will abilities, but given the CR limits they shouldn't be serious. Except for the adamantine horror!