I've made a few small revisions to this thread and reposted it from the old Strategy forum.

Most of the information in this post is based on Tests Summary. Only effective counters are listed. This post is subject to change based upon suggestions.

Format:
Unit:
Its Counters

Infantry

Swordsmen:
Massed Archers, Berserks, Teutonic Knights, Jaguar Warriors, Cavalry Archers, Hand Cannoneers, Janissaries, Cataphracts, Mamelukes, Conquistadors, Scorpions, War Elephants

Spearmen:
Archers, Infantry, Janissaries, Cavalry Archers, Scorpions, Hand Cannoneers

Eagle Warriors:
Infantry, Knights, Cataphracts, War Elephants, Mamelukes

Berserks:
Massed Archers, Teutonic Knights, Samurai, Jaguar Warriors, Cavalry Archers, Hand Cannoneers, Janissaries, Cataphracts, War Elephants, Conquistadors, Scorpions

Huskarls:
Swordsmen, Unique Unit Infantry, Light Cavalry, Knights, Catphracts, War Elephants, Mamelukes, Tarkans

Jaguar Warriors:
Massed Archers, Cavalry Archers, Hand Cannoneers, Janissaries, Conquistadors, Cataphracts, War Elephants

Samurai:
Massed Archers, Cavalry Archers, Hand Cannoneers, Janissaries, Scorpions

Teutonic Knights:
Anything that has a ranged attack except Throwing Axemen and Mamelukes (archers with low attack should be massed), Cataphracts, War Elephants

Throwing Axemen:
Samurai, Jaguar Warriors, Teutonic Knights, Archers, Cavalry Archers, Hand Cannoneers, Janissaries, Cataphracts, Conquistadors, Scorpions, Mangonels

Woad Raiders:
Samurai, Teutonic Knights, Jaguar Warriors, Hand Cannoneers, Janissaries, Cataphracts, War Elephants

Archers

Arbalests/Crossbowman/Archers:
Eagle Warriors, Huskarls, Woad Raiders, Skirmishers, Plumed Archers, War Wagons, Longbowmen, Light Cavalry, Knights, Tarkans, Cataphracts, Mangonels, Scorpions

Skirmishers:
Infantry, Light Cavalry, Knights, Tarkans, War Elephants,
Camels, Cataphracts, Mangonels, Scorpions

Cavalry Archers:
Huskarls, Skrimishers, Massed Archers, Mangudai, War Wagons, Light Cavalry, Knights, Camels, Mamelukes, Tarkans, Mangonels, Scorpions

Hand Cannoneers:
Huskarls, Eagle Warriors, Archers, Skirmishers, Cavalry Archers, Light Cavalry, Knights, Tarkans, Cataphracts, Mangonels, Scorpions

Chu Ko Nus:
Huskarls, Eagle Warriors, Woad Raiders, Skirmishers, Plumed Archers, Longbowmen, Light Cavalry, Knights, Mangonels

Janissaries:
Huskarls, Eagle Warriors, Archers, Skirmishers, Cavalry Archers, Light Cavalry, Knights, Mangonels

Longbowmen:
Huskarls, Eagle Warriors, Skirmishers, Plumed Archers, Light Cavalry, Knights, War Wagons, Mangonels

Mangudai:
Huskarls, Eagle Warriors, Plumed Archers, War Wagons, Skirmishers,
Light Cavalry, Knights, Camels, Tarkans, Cataphracts, Mamelukes

Plumed Archers:
Huskarls, Eagle Warriors, Woad Raiders, War Wagons, Light Cavalry,
Knights, Cataphracts, Tarkans, Mangonels, Scorpions

War Wagons:
Huskarls, Eagle Warriors, Woad Raiders, Massed Spearmen, Massed
Skirmishers, Light Cavalry, Knights, Mamelukes, Camels, Tarkans, Mangonels

Cavalry

Light Cavalry:
Infantry except Huskarls, Knights, Camels, Mamelukes, War Elephants

Knights:
Spearmen, Camels, Mamelukes, Monks, War Elephants

Camels:
Infantry, Massed Archers

Cataphract:
Knights, War Elephants, War Wagons

Conquistadors:
Huskarls, Eagel Warriors, Massed Skirmishers, Light Cavalry, Knights, Camels, Mamelukes, Mangonels, War Wagons

Mamelukes:
Massed Spearmen, Massed Skirmishers, Cataphracts

Tarkans:
Spearmen, Camels, Mamelukes, Knights, War Elephants

War Elephants:
Monks, Missionaries, Spearmen

Ships

Galleys:
Fire Ships

Fire Ships:
Demolition Ships, Turtle Ships

Demolition Ships:
Galleys, Longboats, Turtle Ships

Cannon Galleons:
Galleys, Fire Ships, Demolition Ships, Turtle Ships, Longboats

Longboats:
Fire Ships

Turtle Ships:
Galleys in a ratio higher than 3 to 1

Other Units

Monks:
Light Cavalry, Eage Warriors, Woad Raiders, Cavalry Archers, Archers, Mangonels, Scorpions

Missionaries
Spearmen, Light Cavalry, Eage Warriors, Woad Raiders, Cavalry Archers, Archers, Mangonels, Scorpions

Scorpions:
Light Cavalry, Knights, Tarkans, Cataphracts, Mamelukes, Camels, Mangudai, Woad Raiders, Eagle Warriors, Bombard Cannons, Trebuchets, Rams

Mangonels:
Light Cavalry, Knights, Tarkans, Cataphracts, Mamelukes, Camels, Mangudai, Woad Raiders, Eagle Warriors

Rams:
Non-ranged Units, Mangonels, Bombard Cannons, Mangudai, Mamelukes, Throwing Axemen, Petards

Trebuchets:
Non-ranged Units, Mangonels, Bombard Cannons, Rams, Mangudai, Mamelukes, Throwing Axemen, Petards

Bombard Cannons:
Light Cavalry, Knights, Tarkans, Cataphracts, Mamelukes, Camels, Mangudai, Woad Raiders, Eagle Warriors, Huskarls, Archers, Petards

Petards:
Anything (especially ranged units), but not siege weapons (except for scorpions)

[This message has been edited by Tonto_Stendecca (edited 03-02-2002 @ 00:21 AM).]