Cheat mode:
Press [Enter] to display the chat window and type one of following codes to activate the corresponding cheat function. Note: The codes can not be enabled in a multi-player game unless the host selects "Allow Cheats" check box when the game is set-up.

Effect	Code
1000 stone	rock on
1000 wood	lumberjack
1000 gold	robin hood
1000 food	cheese steak jimmy's
Full map	marco
No shadows	polo
Fast building	aegis
Control animals	natural wonders
Instant victory	i r winner
Instant loss	resign
Suicide	wimpywimpywimpy
Tall, fast moving, useless villager1	i love the monkey head
Infantry unit that acts like a monkey but has 99 attack, 99 armor, 99 range, and 9 HP	furious the monkey boy
Priests have 900 points	hoyohoyo
Shelby Cobra car with twin machine guns	how do you turn this on
Kill indicated opponent	torpedo<number>
Destroy all opponents	black death
Military cars2	big daddy
Saboteur unit	to smithereens

1. This code may not be enabled in campaigns.
2. A car should appear next to your town center. This car can shoot rockets, kill people with one shot, walls with two shots, and town centers with three shots. Note: This does not work unless you have a town center.

Some information in this section was contributed by ChaosCat11, Jonnyg, and mkrats.

Effect	Command line parameter
800 x 600 screen resolution	800
1024 x 768 screen resolution	1024
1280 x 1024 screen resolution	1280
Auto save game	autompsave
Fix display problems with some video cards	Mfill
Fix SoundBlaster AWE freezes	Msync
Disable all music.	NoMusic
Standard mouse pointer	NormalMouse
Disable all sounds except during FMV sequences	NoSound
No pre-game FMV sequences	NoStartup
Disable all terrain sounds	NoTerrainSound

Effect	Code
Build immutable structure	[Ctrl] + P
Alternate resource menu	[Ctrl] + T
Fast construction	[Ctrl] + Q
View ending sequence	[Ctrl] + C

Effect	Code
1000 food	pepperoni pizza
1000 gold	coinage
1000 stone	quarry
1000 wood	woodstock
Animal control	gaia
Full map	reveal map
Instant building	steroids
No fog of war	no fog

Information in this section was contributed by tim

Hint: More bases advantage:
To have a better chance of winning, you might want to build more than one base. Enlarge the base you start out with, making it completely fortified with at least two castles. Then, send a scout cavalry, or some other fast moving unit, to the opposite side of the map from your base. After you have checked the area and confirmed that it is safe, send a villager to build a castle at that location and fortify that base. This is very helpful if your enemy knows where one of your bases are located, especially during online play.
Information in this section was contributed by Brillo2

Hint: Free ally:
When you build a market, there is a chance that a rival tribe will ask you to send them a certain amount of wood, stone, gold, and food. When they do, click on "Diplomacy" or press [Alt] + D and click "Ally" on the name of that tribe. They will become an ally free of charge. However, when you do this you will no longer be able to align yourself with any other tribes. This is helpful if there are four tribes in the game.
Information in this section was contributed by Kevin strickland

Hint: Save resources:
When you are allies with others, do not build a market to avoid giving them resources.
Information in this section was contributed by john

Hint: Multi-player coastal map in single player mode (demo version):
To play the multi-player coastal map with out going online, find the scenario folder and located the "Trial Multiplayer Map" and "Trial Coastal Map". Rename "Trial Muitiplayer Map" to "Trial Coastal Map" and rename "Trial Coastal Map" to "Trial Multiplayer Map". Start the game, select "custom Scenario" and choose on the map name "Trial Coastal Map". When the game begins, it will actually be the Trial multi-player map with four enemies instead of two. Note: Backup the files before renaming them.
Information in this section was contributed by Mandy

Glitch: Demo version losing old saved games on Windows XP:
When you click on the "Age of Empires II: Age of Kings Demo" icon for the first time on Windows XP, it states that you need to reinstall Age of Empires II Demo before you can play it. You do have to install Age of Empires II: Age of Kings Demo again, but you can keep your old Age of Empires II Demo, as well. Once you have installed Age of Empires II Demo again, go to your old shortcut to Age Of Empires Demo and click on it. The game should launch and act as it did when you had your other system, have all its saved names, but some of the music files may not play. Note: You need to have a shortcut to your old Age Of Empires Demo before installing Windows XP and before reinstalling the Age Of Empires Demo.
Information in this section was contributed by micheal egan