There are some differences between the ways that character advancement (i.e. your character gaining levels) works in Pathfinder and in Obormot's Reign of Winter.
Unlike in most Pathfinder or D&D campaigns, you (usually) do not get experience points (XP) for killing monsters. And unlike in the Worlds of Adventure campaign, you do not purchase experience points with treasure.
What gets you XP?
How you do it is at least as important as what you do. Clever, elegant, efficient solutions get you more XP (whether they be shrewd diplomacy and social manipulation, tactically skillful and masterfully executed combat, ingenious applications of magic, out-of-the-box-thinking about exploiting the environment, or anything else). Messy, brute-force approaches, bungled plans that still sort-of-succeed, and "stumbled into success even though we had no idea what we were doing" sorts of "solutions" get less XP. Thinking your way out of situation will often get you more XP than fighting your way out of it.
Of course, the challenge is the challenge, either way, and has to be overcome for the story to move forward, no matter how it's done; even if you get less XP by doing it the dumb way, you've still done it. Tradeoffs must sometimes be made. If you try for an elegant plan that's less likely to succeed, and it fails, well — you pays your money, you takes your chances. But few failures are truly unrecoverable. Enough heroic determination will see you through any downturn.
A final note: XP for the successful advancement of a party's goals is always shared between all members of a group who participate in a plan's execution, no matter which character (or player) came up with it. (This is not true of XP gained for advancing personal goals that don't coincide with those of the party as a whole, though such cases will be rare.)
Instead, in Obormot's Reign of Winter, you earn XP by successfully advancing your goals (which usually, but not always, coincide with the goals of your fellow party members; and also usually, but not always, coincide with the advancement of the "campaign plot"). The majority of the time, this simply means that overcoming the challenges your characters find themselves facing — whether by combat, or diplomacy, or stealth, or guile, or creative use of your character's abilities and/or the environment, or in any other way that you can — gets you XP.
As you earn XP, you spend it, first to gain levels in a primary class of your choice (until you get to 6th character level), and then on — various things; see The E6 System for details. Note that your first six class levels — which get you to character level 6 (the maximum) — must all be in the same character class. (After you reach 6th level, you can "multiclass", gaining some abilities of other classes of your choice; see The E6 System for details.)
The XP cost of advancing a character through each level, starting from 1st level and going up to 6th level, is given on the table below.
Table 1: XP Cost of Levels, 1st through 6th
| Level | XP Cost of Level |
|---|---|
| 1 | 0 |
| 2 | 1,000 |
| 3 | 2,000 |
| 4 | 3,000 |
| 5 | 4,000 |
| 6 | 5,000 |
Note: The table above lists the XP cost of each single level, not the XP total a character needs to accumulate to reach that level. Your first level is free (that is, you start at 1st level, having had to earn and spend no XP to get there), and levels after that cost XP, with each subsequent level costing more XP.
Once you get to 6th level, your leveling days are over; you've reached the maximum possible character level in the campaign, and are an epic character. Not to worry, though! You can still keep gaining character abilities, indefinitely; see The E6 System for details.
