How long does it take to 100% LEGO Batman: Legacy of the Dark Knight?
About 50 hours for a full 100% completion — every WayneTech Cache, Red Brick, Skill Brick, Puzzle Room, AR Trial, Wanted Poster and themed set.
A 100% run takes roughly 50 hours. You need 200 WayneTech Caches, 23 Red Bricks, 30 Skill Bricks, 121 Puzzle Rooms (Riddler + Cluemaster), 30 AR Trials, 7 Wanted Posters, 21 Escaped Zoo Animals, 50 Bat Symbols, 170 Batcave Trophies, and every themed-item set (5 per applicable mission). Several collectibles gate behind characters unlocked later (Catwoman, Batgirl, Nightwing, Talia), so plan to return to early districts in free roam.