Classes and Prestige Classes
Most immortal character will probably become such because of class choices. For some classes it's impossible to avoid; taking the class to completion grants some form of immortality. Here are all the ones that grant any type of immortality.
*Note on Timeless Body*Timeless Body is a
terrible ability for a dedicated immortal. Let's do a quick analysis of it:
"A druid no longer takes ability score penalties for aging and cannot be magically aged. Any penalties she may have already incurred, however, remain in place. Bonuses still accrue, and the druid still dies of old age when her time is up.""Still dies of old age" is bad. It doesn't extend your life at all, merely prevents you from suffering aging penalties. It's not a bad ability to have IF you're a.) already immortal and b.) not immune to aging penalties but it's practically worthless in all other cases.
To help you avoid this trap, here's a list of every class that grants Timeless Body. Remember, these are BAD classes for a character you want to be truly immortal.
Druid (PH), Monk (PH), Alienist (CA), Eldritch Disciple (CM), Dragon Prophet (MoE), Tattooed Monk (CW, Crane tattoo), Contemplative (CD), Sapphire Hierarch (MoI), Initiate of the Draconic Mysteries (Drac), Holt Warden (CC).
That being said, there are a few classes that grant actual immortality:
1. Dread Necromancer (HoH)
The Dread Necromancer is a spontaneous caster focused on necromancy spells. You get some interesting abilities, a good spell list, and the 20th level capstone turns you into a lich. The problem is taking Dread Necro levels past eight is generally a bad idea and it's extremely suboptimal to go all the way to 20 just for lichdom.
2. Cloud Anchorite (Frost)
This is a monk-ish PrC that grants a climb speed and some other abilities, but the real benefit is the capstone. 10th level Cloud Anchorites no longer have a maximum age. The only problem is no class really complements this PrC very well.
3. Beloved of Valarian (BoED)
Unusual in that it grants immortality at level 1, this PrC has fairly strict requirements. You have to be a good (exalted, specifically) female with Vow of Chastity and you lose your immortality if your unicorn mount ever dies. You need +7 BAB and the class has its own spell list, so its clearly designed for martial characters.
4. Green Star Adept (CA)
5/10 casting transformational class that eventually turns you into a construct. The 10th level ability specifically makes you ageless and you pick up a host of immunities on the way. The only problems are the +4 BAB entry requirements and the half spellcasting progression. Probably better suited for a melee-focused gish.
5. Walker in the Wastes (Sand)
This is a very nice 8/10 divine spellcasting class. The class features are nice if not great, but the real prize is the (you guessed it!) 10th level ability that transforms you into a Dry Lich. This is kind of like being a normal lich except you have Unholy Toughness (extra HP based on Charisma) and FIVE phylacteries. You also get fast healing while in a desert (and you spontaneously create deserts due to your aura) and a Constitution-draining touch that gives you temporary HP.
6. Thief of Life (FoE)
It's a rogue PrC that requires you to be a humanoid or monstrous humanoid that worships the Blood of Vol, so it might not be available in your campaign. In addition to a few immunities, the 10th level ability stops you from aging for one year every time you kill someone with a sneak attack. They have to have at least as many Hit Dice as you, however, so you can't just run around ganking commoners.
NOTE: You can actually qualify for this class at 1st level. Take a level of Generic Expert (
here), choose Heal, Knowledge (arcana), Knowledge (religion), Hide, and Move Silently as class skills, and Sneak Attack +2d6 as your bonus feat. Instant qualification at level 1 (thanks to awaken DM golem for the early-entry trick).
7. Incantifier (Dragon 339, contributed by Archmage Joda)
This one is kind of unusual. You need 6th level arcane spells and it costs the same as becomming a lich (120k gp, 4,800 xp) but there's no level adjustment. You don't become undead so much as static; alive, but without any of the requirements of a living creature. You get immortality at 1st level but lose the ability to heal naturally. You eat magic to heal, either by draining items or absorbing spells through your spell resistance. 3/5 arcane spellcasting.
8. Grim Psion (
Here, contributed by Jelvoden)
This is an old 3.0 psionics class from The Mind's Eye series of articles. It was never updated to 3.5, though, so you'll have to do some (minimal) conversion work if you intend to use it. One level will give you undeath and upgrade all your hit dice to d6's at the cost of one manifester level. Taking the rest of this 10-level PrC will net you several lich-like traits (damage reduction, paralyzing touch, d12 hit dice, even a pseudo-phylactery) at a grand total of 4 lost manifester levels. One level is a good choice for immortality-seeking psions, and all 10 are good if you care more about being hard to kill than getting 9th-level powers. Your choice.
Those are the classes that specifically state that you become immortal. However, there are many others that
might grant immortality depending on how your DM interprets them. These are transformational classes that change your type into something that is usually immortal but don't have that listed as a feature. Talk to your DM before you take one of these:
1. Rimefire Witch (Frost)
10/10 divine spellcasting class that turns you into a fey at 10th level.
2. Winterhaunt of Iborighu (Frost)
Another 10/10 divine spellcasting class. You become an elemental with the (evil) subtype at 10th level.
3. Acolyte of the Skin (CA)
5/10 arcane progression. You become an Outsider at 10th level in exchange for sucking as a wizard/sorcerer.
4. Elemental Savant (CA)
8/10 spellcasting focused on energy-themed powers. You become an elemental of your energy type at 10th level.
5. Swanmay (BoED)
Female-only exalted PrC for druids/rangers. 9/10 spellcasting, Wildshape only into a swan, and transformation into a fey at 10th level.
6. Renegade Mastermaker (MoE)
8/10 arcane progression. Become a living construct (like a warforged) at 10th level.
7. Fleshwarper (LoM)
A nearly-full (9/10) progression class focused on aberrant grafts. Transforms you into an aberration at 10th level.
8. Elemental Archon (FP)
The divine version of Elemental Savant with 7/10 spell progression. Elemental of your energy type at 10th level.
9. Heartwarder (FP)
Full spellcasting class focusing on Charisma increases and enchantment spells with a fey transformation at 10.
10. Divine Agent (MotP)
Divine spellcasting class with 5/10 progression. Becomes an Outsider at 9.
I'm sure I missed a few so if anyone knows of one not listed please mention it.
Two Special MentionsIf complete immortality isn't important, you can stack Ruathar (RotW) and Dragon Prophet (MoE). Ruathar increases the length of all your age categories by 50% and Dragon Prophet quadruples your maximum age. This would make you long-lived but not immortal; an elven Ruathar/Dragon Prophet would have a maximum age of around 4400 years.