Mass Effect Legendary Edition
127 Achievements
2915 XP
120-150h
Epic
Scholar
ME2: Unlock 15 new Mass Effect 2 codex entries
10 XP
36.0%
How to unlock the Scholar achievement in Mass Effect Legendary Edition - Definitive Guide
There isn't much to say about this one. You'll get it just as a matter of progression through the game. Most commonly, it will be the primary entries.
Unlike in ME1, gaining these entries (nor the ones in ME3) will not gain you XP.
Unlike in ME1, gaining these entries (nor the ones in ME3) will not gain you XP.
This should unlock naturally just through the story. You will get many new codex entries when taking on new missions and speaking with new characters, and you'll get plenty through the side-quests and loyalty missions as well.