Earth + Water = Mud
Fire + Water = Steam
Earth + Fire = Lava
Water + Water = Lake
Fire + Fire = Volcano
Mud + Water = Clay
Clay + Fire = Brick
Brick + Brick = Wall
Wall + Wall = House
House + House = Town
Town + Town = City
City + City = Metropolis
Metropolis + Metropolis = Megalopolis
Steam + Fire = Engine
Engine + Water = Boat
Boat + Boat = Ship
Ship + Ship = Fleet
Fleet + Fleet = Navy
Navy + City = War
War + Love = Peace
Peace + Love = Harmony
Harmony + Love = Relationship
Relationship + Love = Romance
Romance + Pride = Gay