ECL

From Talus Wiki

Effective Character Level

ECL is added to the current level of the character for purposes of determining Challenge and XP granted.

As an example, a Tiefling has an ECL of 1. This means that a level 1 Tiefling is considered, for purposes of party level and experience, level 2. This character needs 2000xp to reach the next level, instead of 1000xp. In Neverwinter Nights, you cannot change the amount of XP needed to go up a level - so the experience earned is scaled. The Tiefling will get 50% of all XP that a normal character would get. When he reaches 1000xp, a regular character doing the exact same things would have earned 2000xp. In short, though it may not reflect on the character sheet, subraces with ECLs work correctly, as defined in D&D rules.