Regicide (game mode)

Regicide is a game mode avaliabe in Age of Empires II. It starts as a normal game, but each player starts with a Castle, and a special King unit. You must defeat the opponent's King to defeat them, and you lose if your king is lost.

Strategy
King units cannot do anything, so garrison him in your castle and guard it carefully. Play as you normally would in a Random Map, but don't bother attacking yet. You can spend gold to research Treason from your castle, which temporarily shows where the opponents kings are hiding, usually in their respective castles. Gather a small army of siege weapons and other units, and break through to the opponent's castle. When the castle falls, the King will probably retreat to the Town Center. If you can't defeat him before he garrisons himself again, then have your siege attack the center, and have other units remove villagers attempting to repair it.

NOTE: Kings are among the fastest units in the game.