Battle Jobs are professions meant primarily for combat. Most job classes in Ragnarok Online and Ragnarok Online II consist of battle jobs. Unlike many other MMORPGs on the market, the Ragnarok Online series feature branching job tiers that players can advance through as they level up.
Every player starts out as the basic Novice Job Class in Ragnarok Online. From here, players can choose from one of 5-6 1st Class jobs to progress in the game. However, players who like the versatility of the Novice can advance to a Super Novice if they so choose. The Novice is absent as a playable job class in Ragnarok Online II.
The second level of jobs is known as the 1st Classes, which consists of Swordsman, Acolyte, Thief, Magician, Archer, and Merchant. From here, the job classes begin branching off from 2nd Class onward. Once a player has chosen a particular job path, he/she cannot revert back to Novice. The Merchant classes are absent in Ragnarok Online II in favor of allowing all players the ability to vend and craft weapons and potions.
In Ragnarok Online, each 1st Class job is split into two paths, totalling twelve 2nd Class jobs that players can choose from. From here, players can take many other job paths: one could progress to 3rd Class jobs; or advance to a Rebirth Class and go through the job path again to finish with a 3rd Class job; or progress to a Rebirth Class and remain there. In Ragnarok Online II, players can choose to progress their 2nd Class job to one of 2 tendencies: Order or Chaos. Depending on which Khara the player leans toward, their character will perform differently.
In Ragnarok Online, Rebirth Class jobs are jobs that can only be gained by dying and then reborn with the blessing of a Valkyrie. Once reborn, players will progress through an advanced version of 1st Class jobs to arrive at their new Rebirth Class job. From here, players can choose to either remain a Rebirthed or take the next step to 3rd Class. (On iRO, this tier is known as Transcendent.) There are currently no Rebirth Class jobs in Ragnarok Online II, but they are in the works.
The 3rd Class jobs are advanced versions of existing 2nd Class jobs in Ragnarok Online. Players can advance to them from a 2nd Class job or a Rebirth Class job. There are currently no 3rd Class jobs in Ragnarok Online II, but they are in the works.
The 4th Class jobs are currently the highest tier of jobs in Ragnarok Online. Players advance to them from 3rd Class jobs.