As far as i know, Koei does not seem to publicise cheats for their Romance of the Three Kingdoms series of games. If you are those rare few who happen to know/discover any cheats, why not share them if the rest of the other Rtk gaming fans around the world?

You can do so by emailing me the cheats for whatever Rtk games you know and credit will be accorded to you.

Rtk VII japanese

Control of more than 1 person - Dennis Lim
In the Japanese version of RTK 7, you can cheat. If you do the following, you can get a special menu that lets you control more than one person at the same time.

1. Hold down the SHIFT button on the right hand side of the keyboard
2. Hold the left button of the mouse
3. Right-click twice

Rtk VI

Hidden Stuff - Han Zhang
Select one of your cities and then right click on Taiwan, something happens (forgot exactly what. . . )
Right click on your capital city, something happens
Right click on Hainan Island, something else happens. . .

Rtk VI playstation

Champion class officer - Yosef Ho
Create a 29 new officers/generals with the type of "OFFICER," and when you create the 30th officer- the 8th hidden type of officer will open, " CHAMPION." This champion type will have all the starting ability around 95. And have most all of abilities in duel, except secret (because you need special weapon to get secret ability ). Please note that this Champion type only come up for the 30th officer only-and only can be used one time. I have been trying to create this champion type by deleting the previous character but still it cannot work. Thus, this champion type only can be used by one character.

Alternate Champion class officer method - sly
When building your own officers there are a few Names you could input to obtain special statistics. Enter Name:

Last: Bruce First: Lee
Continue creating your character as a TYPE:Warrior Class(Make sure his War skill reaches 100). Now that the Character is created Select: Modify Character. Next change his abilities, you'll notice right away when you try to change the TYPE it will display the usual,
Original
Officer
General
Warrior
Strategist
Minister
Retainer
***CHAMPION*** this is the new class which will be available to you it allows you to have ALL stats between 90-100. There are a few more Chinese and Japanese Icons you could put as a special name.

Selection of all types of troops - Hubert Hu
When you are drafting soldiers and have the troop type selected, press select button 3 times before choosing it and you'll be able to select all the types of troops.

Change player - sulung chandra
You can change your player when you play the game individually. I had never try to play multi player in that game, unfortunately. Remember you cannot change your player when you are playing short scanario

Details:

1. start by playing individually
2. when it is your turn, click 'select' and choose 'quit'
3. choose the one that allow the computer play the game for u
4. after the computer play for u, click 'select' again
5. click until a message is shown. if i am not wrong the message read as "set a new player?"
6. click 'ok' and choose your new player.

Make a new king - sulung chandra
I was able to use Zhao Yun as well as to make him a king of Chu. I don't know whether the other generals can be kings. The period should be the one when the emperor has no power. I was playing the scenario when "liu bei becomes king of Han Zong"

Details:

1. choose liu bei as a starting player
2. decrease the loyalty of Zhao Yun by taking and giving him items repeatedly.
3. make him a warleader.
4. after he rebel, change player and choose zhao yun as your new player.
5. conquer 'jing' region
6. talk to your generals.
7. they are the one who will make u a king

This cheat may NOT work with you because i just tried it once.

Rtk IV & V

Playing other computer controlled warlords - Vincent Boey
When you are playing a ruler and do wish to play the other rulers which the computer is controlling,then you can quit the game and say yes when the computer prompt you whether you wish to see the game played entirely by the computer.Then,click your left and right button of the mouse at the same time and simultaneously to bring up a menu.This menu will then let you play any rulers at the time of the game.

or as suggested by Josh:

For Rtk IV playstation, if you quit and let the computer play you can press select and pick a ruler and play as them.

Rtk IV

Gaining up to a maximum of 150,000 troops in battle - Keith Bitting
In rotk IV I know of only one cheat and that is a way to manipulate the troop system to basically give you an infinite number of troops. Let me see if I can recall it correctly, First you go to war. Choose a general for each spot then assign as many troops as you can to anyone of them up to "300" or 30,000. Then click ok but when it says are you sure say no. Now deselect your Generals then reassign them exactly as they were but "remove then reassign". Go back to your troop screen and you will have double the men you had before allowing to repeat this step till you have the maxium number of troops allowed in a battle "1500" or 150,000. Note you can get more men but you will only KEEP the ones that went to battle or the maximum 1500. This is the only cheat I ever knew of and discovered it by accident although i would never use it, for one the game is already way to easy and its a quite lame way of saving your ass.

Unlimited Soldiers - Nintendo version - Trevor Lake
For nearly unlimited soldiers, perform the following actions.

1. Start a war.
2. Choose your officers normally, but create 2 or more units.
3. Go to the next screen by pressing the A button in "Enter".
4. Put 1 soldier in each unit, and all the others in one unit.
5. Press "Enter".
6. The game will ask, "Are you ready to start battle?" Choose NO.
7. You will back to the unit-creating screen.
8. Dismiss the unit that you choice in step 4 and re-create it.
9. Press "Enter".

Now you should have two times the amount you put in. Do this as many times as you want.

Rtk III

Makes enemy general's loyalty drop suddenly - Daniel Ongkowidjaja
You must ally with the target ruler, make sure that this alliance is successful. After doing that you must threaten the target ruler twice, than attack the nearest city with only 1 general, make sure you withdraw that general as soon as the war begin. Tadaaaaaaa, the loyalty of generals who serve the target ruler drops by aproximately 20 points.

Rtk II

Unlimited Gold & Men - Han Zhang
Unlimited Food (implies unlimited gold and men, as u can sell food for gold, and use gold to hire men): Select a province (poorly developed hopefully), move 1 general out of that province. Take 0 gold, and for food, just type enter (ie don't type any numbers in). The result of that is that the amount of food in the destination province will increase by approx 80000.