In Final Fantasy XIII, the Crystarium board was split into different tiers, and as you defeated certain bosses you unlocked more of it. In XIII-2 though, the Crystarium is completely open from the start, allowing players to level up as much (or as little) as they choose.
Jump has the first look at the newest version of the system. The board itself is in the shape of Noel or Serah’s weapons, depending on who’s you are leveling. The tiers are completely gone it seems. You will still need to spend CP to gain new abilities, but the system has been refined to make it a lot easier. By completing cetain conditions for certain roles, you’ll be able to select from several bonuses for you character, for example.