Subclasses: Select one in addition to your standard class
Each subclass has a bonus feat (applied at the first level) and a crystal skill. The bonus feats typically add some minor bonuses to the characters to compliment the subclass. The crystal skills allow you to make use of the various crystals that are used as the primary currency on Peth. I would recommend that a party include a variety of subclasses to get the most out of the crystal system.
The Explorer can use crystals to cast increasingly powerful movement and survival spells.
The Quartermaster can use multiple crystals to apply permanent bonuses to weapons and armor.
The Transmuter can combine weaker crystals into much more powerful types.
The Protector consumes crystals to erect powerful defensive auras for the party
In Urath, the exchange rates for the crystals are as follows:
Crystal Type         Level     1             2             3             4             5
Earth                                      50          100        200    400      800
Fire                                        100        200        400    800      1600
Water                   100        200        400    800      1600
Wind                                     200        400        800    1600     3200
Crystals above level 5 may be possible, but they would have to be mythically rare indeed.
–Explorer–
Bonus Feat: Hunting
The Explorer can extract crystals from slain creatures more easily due to years of hunting, skinning, and butchering game. Every time you find a gem in a dead creature, roll a d20. 1-10 means nothing, 11-17 means you find an additional gem of the same type, 18-20 means you find another gem of a level 1 higher than normal.
Crystal Skill: Exploration Spells
The Explorer can clutch an elemental crystal in his palm (or appropriate extremity) and consume it. Select the spell from below. These spells can generally be used to bypass terrain and give you resistances against nature.  This list assumes that you have a crystal of the appropriate type and level; the crystal dissolves into magical energy and the chosen spell immediately takes effect. For example, with a level 3 Earth crystal you could cast animate rope or transmute mud to rock, but you would require a level 5 Earth crystal in order to cast iron body. In all cases the spell’s ‘caster level’ is equal to the used crystal’s level times 2. There are no level restrictions on any of these spells.
Earth crystals: Lv 1,2 Animate Rope: Makes a rope move at your command.
Lvl 3,4 add Transmute Mud to Rock: Transforms two 10-ft. cubes per level. or
Transmute Rock to Mud: Transforms two 10-ft. cubes per level.
Lvl 5 add “Iron Body: Your body becomes living iron.
Fire crystals: Lv 1,2 Spider Climb: Grants ability to walk on walls and ceilings.
Lvl 3,4 add “Freedom of Movement: Subject moves normally despite impediments to movement.
Lvl 5 add “Ethereal Jaunt: You become ethereal for 1 round/level.
Water crystals: Lv 1,2 Endure Elements: Exist comfortably in hot or cold regions.
Lvl 3,4 add “Solid Fog: Blocks vision and slows movement.
Lvl 5 add “Polymorph Any Object: Changes a subject into anything else.
Wind crystals: Lv 1,2 Status: Monitors condition, position of allies.
Lvl 3,4 add “Air Walk: Subject treads on air as if solid (climb or descend at 45-degree angle).
Lvl 5 add “Reverse Gravity: Objects and creatures fall upward.
–Quartermaster—
Bonus Feat: Regular Maintenance
Quartermasters treat all their equipment as if it had a bonus +2AC if they are at risk of being destroyed by a creature, acid, magic, etc. If an item would be destroyed by magic or a creature, you may reroll the action that destroyed the item once to try and save your item; this can be done for only a single item per round.
Crystal Skill: Runecarver
A Quartermaster prides himself on keeping his equipment in correct repair, and the best quartermasters can make use of certain slotted weapons, increasing their power. A quartermaster can use 5 of any gemstone of the same type and level and use its energy to affix a large runegem, infusing power into the weapon or armor. You may use some gems of higher level of the same element, but they will not contribute to the level of the runegem (i.e., using level 1, 1, 1, 2, 5 gems would give a lvl 1 runegem). Once a runegem has been set, it cannot be removed without destroying it unless they peel away the weapon; the PC must choose to preserve the runegem OR the weapon, but they cannot save both! A removed runegem can be added to a weapon or armor for no crystal cost, but you must wait the full 8 hours for the runegem to take effect just as a new one would.
It takes a quartermaster the span of a day’s rest (8h) to perform his/her work. A Quartermaster can only infuse 1 runegem per night per 5 character levels(i.e. 2 runes at lvl6, 3 runes at lvl11…) (it doesn’t TAKE all night, but the process requires that the PC stay vigilant as to the progress of the runes. They still gain spells, are rested, etc.)
Most slotted armors and weapons have but a single slot, but in some legendary cases a weapon with more than one slot could be possible.
Earth crystals: Infusing a weapon with an earth crystal will add acid damage to it. Acid will deal it’s minimum damage on the damaged creature’s next turn.
Weapon                                                Armor                   Level Req to craft
Lv1 – 1d3 acid damage                      +2 total HP                           1
Lvl2 – 1d6 acid damage                     +3 total HP                           3
Lvl3 – 1d8 acid damage            +4 total HP                           5
Lvl4 – 2d4+1 acid damage                +5 total HP                           8
Lvl5 – 2d6 acid damage                     +7 total HP                           13
Fire crystals: Infusing a weapon with a fire crystal will add fire damage to it.
Weapon                                                Armor              Level Req to craft
Lv1 – 1d4 fire damage               +2 Initiative bonus              1
Lvl2 – 1d6+1 fire damage            +3 Initiative bonus              3
Lvl3 – 1d8 fire damage             +5 Initiative bonus              5
Lvl4 – 1d10 fire damage                      +6 Initiative bonus              8
Lvl5 – 1d12 fire damage                      +8 Initiative bonus              13
Water crystals: Infusing a weapon with a water crystal will add cold damage to it. Cold damage can have special effects depending upon the circumstances.
Weapon                                               Armor                   Level Req to craft
Lv1 – 1d3 cold damage                      +1 elemental absorption                  1
Lvl2 – 1d4 cold damage           +2 elemental absorption                  3
Lvl3 – 1d6 +1 cold damage         +3 elemental absorption                  5
Lvl4 – 1d10 cold damage                 +4 elemental absorption                  8
Lvl5 – 1d12 cold damage                  +5 elemental absorption                  13
Wind crystals: Infusing a weapon with a wind crystal will add electricity damage to it.
Weapon                     Armor             Level Required to craft
Lv1 – 1d6-1 elec damage      +1AC                         3
Lvl2 – 1d8-1 elec damage      +1AC, +5ms                   5
Lvl3 – 1d12-1 elec damage     +1AC +5ms +1Saves             8
Lvl4 – 2d8-1 elec damage     +2AC +10ms +1Saves            11
Lvl5 – 2d10-2 elec damage    +2AC  +10ms  +2Saves           15
 –Transmuter—
  Bonus Feat: Connections
Transmuters are known to have vast networks of traders, whether it be via the doors of planes or with the various creatures that help fill this role. Therefore, the Transmuter is assumed to have some level of familiarity with a wide variety of cultures, and therefore the PC gets a permanent bonus of +3 to all Appraise, Bluff, and Diplomacy checks. Bonuses may also apply if the Transmuter wants to get area knowledge or find a particular person or burg (DM’s discretion).
  Crystal Skill: Trade Channels
Whether it be via a magical spell or by sly trade with the local Chimp Imps, transmuters know how to get the type (and quality) of crystals that they need. Given a night of rest, a transmuter can trade in crystals for crystals of a different type or of higher quality; whether this is done by clever mercantile or by shifting the planes to shape reality is up to the character’s style. This crystal skill can be used a number of times per day equal to the character level divided by 2, rounding up (i.e. a level character can use this power 3 times a night).
When transmuting a crystal from a lower level to a higher level, you must be of a character level as stated in this chart:
Crystal Upgrade                                                   Level Required
Lvl1 to Lvl2Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 1
Lvl2 to Lvl3Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 3
Lvl3 to Lvl4Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 5
Lvl4 to Lvl5 Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 7
3 Earth crystals -> 1 Fire CrystalÂ
4 Earth crystals -> 1 Water Crystal OR 1 Earth Crystal of 1 higher level
5 Earth crystals ->Â 1 Wind Crystal
3 Fire crystals -> 1 Earth Crystal
4 Fire crystals -> 1 Water Crystal OR 1 Fire Crystal of 1 higher level
5 Fire crystals ->Â 1 Wind Crystal
2 Water crystals -> 1 Earth Crystal
4 Water crystals ->Â 1 Fire Crystal OR 1 Wind Crystal OR 1 Water Crystal of 1 higher level
2 Wind crystals ->Â 1 Earth, Fire, or Water Crystal
4 Wind crystals -> 1 Wind Crystal of 1 higher level
–Protector–
  Bonus Feat: Desperate Defense
If a member of the Protector’s Party falls to 0hp (that is, if they are disabled, not necessarily dead), the Protector immediately gains +2AC and +10 movement speed for 3 turns. This effect stacks if multiple characters fall (i.e. if two party members fall, you now have +4AC and +20ms, duration is reset to 3 turns). Your protector must be aware of the character falling in combat to take this benefit.
  Crystal Skill: Bond
Whether it be a healer or an armored defender, the Protector allows the character to consume crystals to cast powerful charms that will empower his allies.
Unlike the explorer, all skills that require the consumption of a crystal will affect all allies in a 15ft radius (diameter 30ft centered on the Protector). There are no spells; this is treated as a spell-like effect. The levels in the following chart refer to total character level except where specified. A Protector can cancel any effect prematurely. All Bond skills gain additional benefits if a level 4 or higher crystal is used. There are no level restrictions on the use of these crystals. However, the Protector can not use a number of crystals in a given day greater than his level (i.e., a 10th level Protector could use Domain 10 times a day with 10 total Earth Crystals being consumed.)
  Earth crystals
  Domain: All party members in the area heal 1d6+CL damage for X turns, where X is the level of the crystal used. If a party member wanders out of the range of this spell, then Domain does not affect them that turn. Domain does not move with the caster; it remains centered at the point of casting. If the character should reenter the range of the spell before it expires, the character will start gaining HP on their turn as normal. For example, a level 4 fighter that used Domain with a level 2 crystal would heal 1d6+4 damage in the area for 2 turns. Roll once each Protector’s turn to see how much healing the party receives each turn.
  Improved Domain: With a level 4 crystal or above, any healed character receives a +1 chance to hit on all physical attacks for the duration of Domain. In addition, all characters gain an additional +10 bonus HP for the duration (not per turn).
  Fire Crystals
  Prison: A large, 30ft by 30ft circular prison made of 6-in thick iron materializes around you. If there are any living beings in the potential path of this prison, then the prison does not materialize and the crystal is lost.. This prison is mostly solid walls, with a few barred windows every few feet. The ceiling of the prison looks much the same, with barred windows every few feet allowing in light; it is 10ft above the floor. The prison is incredibly strong, and can be used to regroup while under assault, to provide cover, or to separate groups of enemies into an ‘arena’ to kill them separately. The prison lasts for 1 minute per crystal level. Nothing short of being smothered in lava or other such catastrophic damage will damage the prison faster than it would disappear anyway.
  Assault Prison: With a level 4 crystal or above, the prison will have several turreted staircases that lead to the top 5ft of the prison. These have arrow slits that provide half concealment while allowing you to fire out. There are also now spears that will be lining the prison on all sides, that (when used by a medium creature) deal 1d10 damage. These spears disappear when the duration is up on the Prison. There is a pit 10×10 near the center of the prison that is filled with jagged, hateful spikes; these spikes will deal 2d8 damage to anything that remains in it so long as they struggle. There is a giant mechanical chain with jagged spikes on the outside, constantly churning like a chainsaw; they damage anything attempting to climb or otherwise assault the prison for 2d8 damage per turn.
  Water crystals
  Liquid Reflex Barrier: A paper-thin barrier of magical water surrounds the party. This barrier does not affect anything coming OUT of it in any way. Any magical or mundane attacks that come through the barrier will appear to be much slower and weaker, and as a result the party gets a +1bonus to all saves per crystal level while within the barrier (so up to +5). This barrier lasts 1 minute per 4 character levels, and does NOT move with the caster.
  Liquid Deflection Barrier With a level 4 crystal or above, in addition to all above effects, all incoming arrows and ballista bolts have a 50% chance to miss when fired from outside of the barrier to inside of the barrier. Siege weaponry and other large projectiles allow a reflex save for half damage.
Wind Crystals
   Zephyr Spiral: An energizing stream of wind pours from the crystal, empowering the party and increasing their reflexes significantly. Add 1AC per crystal level to all characters within range of where the crystal was used for 1 minute per crystal level. This bonus does not apply if the characters are prone or otherwise flat-footed. This effect does not apply if the characters move away from the casting spot, as Domain above.
       Zephyr Helix: With a level 4 crystal or above, in addition to the above effects, all enemies have sand thrown in their sensory organs DC(10)+(crystal levelx2)+(1/2 CL) modifier), and they are blinded for 4 +1d4 rounds if they begin the duration of the spell within range. If a creature enters the range after the spell has started, then they make a fortitude save DC (10)+(crystal levelx2)+(Wis modifier) to see if they are blinded for 4+1d4 rounds.