Reference
Exactly what Celts can train, build and research, by age.
Infantry and Siege civilization
•Lumberjacks work +15% faster
•Livestock animals within Celt unit line of sight cannot be stolen
•Infantry moves +5/10/15/20% faster in Dark/Feudal/
•Castle/Imperial Age
Team bonusSiege Workshops work +20% faster
51 units · 28 buildings · 68 technologies. Each building carries what it trains and researches; upgrades sit under what they upgrade from.