Ascension

It's possible for a player character to change his or her class even after a character is rolled–no change is permanent. There are advantages to a class change, especially if you've changed race, too. There are racial and class bonuses and affects that could be beneficial in one case as opposed to another.

From "help ascension:"

Ascension:

Usage: ascension
Usage: ascension <subclass name>

Ascension is the next step of progression for those who have achieved
the maximum augment level. For more information on augments, see
'help augment limit'.

The ascension command allows a player to advance beyond the normal
augment limit. Doing so provides two benefits - the ability to further
augment her pool and stat caps, and the ability to choose additional
subclasses (thereby learning their unique abilities).

The overall progression of augments and ascension is as follows:

  1. After augmenting to maximum (71 augments), the player gains a new
     title.
  2. Using the 'ascension' command with this new title will allow her to
     begin augmenting again, starting at 1. All benefits from the
     previous augments are retained, and a new subclass is chosen -
     she now has the unique abilities of two subclasses.
  3. After augmenting to maximum again, she may then ascend once more, 
     again restarting the augment process and gaining a third subclass.

This progression is summarized in the table below. Advancement from one 
tier to the next requires the use of the 'ascension' command.

  Tier 1:   ( aug-# ) --> ( ascend )
  Tier 2:             --> ( asc-#  ) --> ( legend )
  Tier 3:                            --> ( lgd-#  ) --> ( demigod )

The player possesses one subclass in Tier 1, two subclasses in Tier 2, and 
three subclasses in Tier 3.
  
For very important information on the costs and limitations of 
ascending, see 'help ascension limitations'.