You get XP in the module for completing scripted quests, participating in DM quests, roleplaying and for killing things.
All XP is stored until you use it to level up, (see Levelling Basics below) so you cannot see how much you have. The soul stone basic information can give you a general idea of how close you are to the XP needed for the next level, but the exact amount is hidden.
You will only see messages like “You have gained some XP”
All the scripted quests give you some XP upon full completion. Some also give you XP for completing sub-parts of a quest. The amount you get for each quest is normally not high.
DMs give out (fairly small) XP rewards for characters participating in the DM quests. Good roleplaying can be rewarded with similar XP awards if noticed by DMs.
When you kill things (that you are supposed to be killing) you get XP depending on their power.
Basic XP amount is larger of: (Creature XP level*10)-(Your level*5) or (Creature XP level*5)
This XP is divided among party members, though the first five extra people in the party each add +10% to base.
Further it is modified by the number of the same creatures you have killed before:
Your first kill is worth five times as much, second twice, and any kills in excess of twenty give you only half experience and finally at over fifty kills you get no XP. (These awards represent the fact that killing same things again and again is not likely to teach you anything new.)
In order to be able to level up you need to have enough XP, enough Reputation Points and then get training.
Each time you get more XP after having enough to level up, you will get a message indicating that you should get training to level up.
In order to get the trainers to train you, you will need to use reputation points.
The cost in reputation points is (New level)^2 - (Current level)^2.
Thus to gain level 2 you will need to spend 3 reputation (2^2-1^2=4-1=3); to gain level 3 you will need spend 5 more reputation points(3^2-2^2=9-4=5) and so on.
Another limitation is that your total all-time gained reputation sum has to be atleast twice the new level squared. (2*(New level)^2).
Thus you need to have gained a total of 8 reputation points to reach level 2, 18 for level 3 and so on.
You will need to convince a NPC trainer to train you to the next level.
This means paying the reputation cost and usually something else as well.
Each trainer can only train one level for you. You will need to find another trainer for the following level.
There are three basic ways to get a trainer: Pay them, Help them or join a guild.
Some NPCs train others for money. You will thus need to find them and pay them to get your training.
Doing some quests to help some NPCs will cause them to offer to train you in future as a quest reward.
Almost every guild will have a guild trainer that is available to apprentices and higher ranking members.
In order to gain a prestige class, you need special training.
Normally, you can get special training needed by joining suitable guilds. See the prestige classes trained in the guild list.
You need to join the given guild and talk to the special trainer and pay the training price.
Reputation measures your “impact” on the world.
You have two reputation scores:
One is the total number of reputation points you have gained. This measures your overall fame.
The second is how many unused points you have. By using these points, you can get “favors” from NPCs.
There is also a longer discussion on reputation.
You gain reputation points in many ways:
In general, the scripted quests and DM quests are the fastest way to get reputation, but a determined explorer will certainly gain a lot.
The reputation points have many uses.
The most common are getting training to raise levels, getting NPC recommendations in order to raise guild ranks, raising in Social status and getting some inworld things like permanent housing, NPCs or placeables.