This page will serve as a checklist for concepts of the game you should understand.
Basic
Castle Set-up
Outposts
types and their advantages
capturing
Towers and Walls
Troops and Tools (melee vs ranged)
Defense Wall Set-up
Attacking and Defending RBCs
Managing Food/Troops in your Castle
Managing Rubies for the Resource Player
Looting and Plundering
Managing Honor
Traveling Knights Event
Shady Character
Intermediate
Equipment- Building Commanders and Castellans
Everwinter Glacier
Attacking Barbarian Towers
Attacking the Barbarian Fortresses
Capturing Resource Villages
Achievements
Upgrading Villages
Research
Veteran Soldiers
Elite Soldier training
Events (Adventures)
Nomads
The Thorn King (Level 40, 35 ruby player)
The Blades Coast (Level 40, 35 ruby player)
Storm Islands
Renegade Spy (Ice and Sands)
Spy Camp (Evergreen Winter)
Advanced
Desert Sands
Fire Peaks
Attacking Sands Tower (same as Barbarian)
Attacking Sands Fortress
Attacking Fire Fortress
Capturing RVs, access to:
Level 3 Stables
Wolfhounds Access
Accumulating Glory and Honor
Alliance levels
Alliance rankings
Titles and their rewards
Glory Tournaments
The Battle of Berimond
Monuments
Labs
Mass Attacks
Tool Wipers
Royal Towers
Metropolis
Capitals