Basic Information
Character level is a feature of RPG systems which divide a character's development into a number of discreet, discontinuous levels. Broadly a character progresses from one level to another by hitting a series of metrics (which are often genericised "experience points" but may be other things such as kill-count, successful skill checks etc.), at which point they are rewarded with another tranche of development - such as improved combat and non-combat skills, added "hitpoints" and the like (sometimes including the ability to add statistics points and feats or edges). Reward is a key word here - "levelling" is often a key motivational factor for players as well as characters.
Level based systems provide for clear progression in a character's career and can make it easy for a GM to judge appropriate challenges, but have the handicap that they tend to require near-worthless starting characters and progress them to godlike power, that levelling up different character builds can lead to radically different power progressions within a party and that the sharp discontinuity between levels can strain verisimilitude. Not to mention the bizarreness of skills that the character has not used improving on level up and that of a world-class skill in one field necessarily requiring high skills in others1.
Obviously a non-levelling system lacks this feature (known as the "power curve") - experienced characters may well be better than inexperienced ones (as indeed they should be) but not by such a staggering degree - this allows the campaign to start with significant encounters (since the characters don't need to begin as steaming incompetents2) and end without the characters having "no worlds left to conquer". Given sufficient scope, you can start as a world class swordsman or powerful wizard - or equally as someone's ratboy - the feel of system will be a lot different. In particular, a curve-free setting allows a more picaresque campaign - since your characters are not on an ever escalating path to power, there is no need for an epic plot or every increasing difficulty … depending on the power level the campaign is set at, the type of threat can be kept pretty steady and merely adjusted up and down for available resources.
This is the other key mechanic of the class and level system, but can also appear in other systems.
Sources
Game and Story Use
- This is a key part of the Dungeons and Dragons RPG and its various descendants.
- But also something of a marmite mechanic.
- The levelling curve can do quite a bit to simulate the bildungsroman sort of narrative where aspiring heroes come into their full power and might, but less to simulate classic adventure novels such as the Conan cycle (where, once grown to manhood, he learns a thing or two but does not get significantly more able) or Lord of the Rings (where Frodo and Sam may undergo significant development, but most of the Fellowship start off as high achievers and don't change much3).
- The power curve can almost make high and low level play like two separate games - a lot of what was suitable for low level characters (dungeons in particular) becomes trivial and unchallenging for high level ones (or has to be forced hard). It can also have unfortunate effects on the game world - a setting which is congruent and playable for low level characters is tissue paper for high level ones, and the GM will need to constantly unearth stashes of more powerful opponents for the PCs to kill. Not to mention that it is all too easy in some systems for a PC to hit the level cap in their early twenties (seriously - a human 3.5 D&D character can start at 16 and, if adventuring continuously, especially with 3.5s obsession with "level appropriate" challenges and rewards, could well be epic level by the time they are out of their teens…).
- There are some "hacks" in place - one of the best reputed ones out there is the E6 or "Epic Six" hack for the Pathfinder RPG which caps PC level (only) at 6 (roughly the point when things start to get silly in a standard game) with slow polishing improvements beyond that point rather than further levelling. Rare NPCs, monsters and the like can still level (or equivalent) far above 6, meaning that players will need to work for their victories rather than expect to simply go toe-to-toe with the BBEG when they hit an appropriate level.