Ok, I've heard about some people new to Total War (my brother included) find fighting battles in person difficult. I am looking to rectify the situation, because battles are, in my opinion, one of the best things about Total War games. This is my first guide, so any feedback from people like Dark Side who have made guides before will be appreciated.
Units Types and Weaknesses/Strengths
There are six units types in Shogun 2:
Cavalry: Dudes on horses e.g. Light Cavalry. Vulnerable to Spears, and, at a distance missiles.
Sword Infantry: Dudes with swords e.g. Katana Samurai. Very good against Spears and other Sword Infantry. As with all units, missiles can damage heavily at a distance.
Spear Infantry: Dudes with spears e.g. Yari Ashigaru. Excellent against Cavalry, bad against Sword Infantry and vulnerable to missiles at a distance.
Archers: Dudes with bows e.g. Bow Ashigaru. Good against everything at a distance, but can be very vulnerable in melee.
Matchlocks: Dudes with guns e.g. Matchlock Ashigaru. These guys are excellent against armour, but terrible against everything in melee.
Siege Units: Dudes with bombs e.g. Mangonels or Fire Bomb Throwers. Good for reducing morale and for breaking fortifications, but horrible in melee.
Now units are covered, I will go into some basic tactics that I use against the AI.
Use of Cavalry
1. Flanking. This can be used to take out the enemy general or missiles, or harass the enemy and make them pull Spear Infantry away from the main force in pursuit of the Cavalry. This is especially good with Bow Cavalry.
2. Charging. This is used to kill enemy units. This is especially effective with Yari Cavalry, but watch out because they are pretty bad in melee. Katana Cavalry have a meh charge, but can survive a long time in melee and do alot of damage. It's best to charge into the sides or back of enemy units, but watch out for Spearmen who will decimate your Cavalry, and Missiles who will cause alot of damage at a distance as horses are big targets.
3. Kamikaze. This is where you charge your cavalry straight into the front of their force, basically. It ties them up and allows your units to form up/move forward or whatever. Your Cavalry will also cause damage in melee and in their charge. You will most likely lose your Cavalry, so only use in very desperate situations!
4. Repeat Charging. This is where you charge into an enemy unit, then pull your Cavalry back for another charge. Very effective with Yari Cavalry, because they are vulnerable in melee and charge effects are very devastating to enemy units.
Use of Infantry
1. Forming and Holding Lines. A line of infantry will provide great cover for your missile units and will hold enemy melee units in place, for flanking maneuveurs.
2. Flanking and Rear Charging. An infantry unit can circle around your line and charge into the side or back of an engaged enemy unit, damaging it's morale severely and causing alot of damage.
3. Guarding. If you have Siege units such as Mangonels or Missiles such as Archers, you might want to keep some Spear Infantry back to protect against Cavalry charges.
Use of Archers
1. Skirmishing. Place your archers in front of your infantry with Skirmish Mode enabled (Bottom left corner of the screen, along with other unit abilities) and they will fire at the enemy, then run back behind your melee when the enemy Infantry move in to attack them and can then carry on shooting in relative safety. They damage morale and can rout injured units. Some Archer units have Flaming Arrows and Whistling Arrows, which cause morale damage.
2. Siege Defence. Archers are devastating in Siege Defence, often being able to kill alot of units before they run out of ammo due to the protection of the castle walls.
3. Archer Duels. This is where your archers and theirs have a shoot-out. Move into loose formation and your Archers will win almost every time.
4. Siege Attack. They can burn down buildings and shoot into the enemy castle to kill their melee units.
Use of Matchlocks
1. Skirmishing. Same as the Archers, really, although you might want to disable Fire At Will after they move behind your Infantry, otherwise they will shoot your own Infantry in the back! However, if they are on high ground they can shoot over the heads of your men and cause massive casualties to the enemy Infantry. Matchlocks are devastating against morale and can send an Ashigaru unit fleeing before it even reaches them.
2. Siege Defence. These guys are insane in Siege Defence. They can tear apart units before they even reach the walls, as can Archers, but far quicker due to the morale damage from Matchlocks.
3. Flanking and Shooting. You can move your Matchlocks behind the engaged enemy melee(watch out for Cavalry!) and shoot them in the back. This is very effective as the Matchlocks won't hit your men as much and hit the enemy very hard.
Use of Siege
1. "Sniping". With Cannons, it is possible to shoot the enemy general early on in the battle. This is frowned upon in multiplayer, so if you move onto that, refrain from using this.
2. Siege Attack. Walls cannot be destroyed in Shogun 2, but you can destroy the defences that Archers use and make any archer duels fairly matched.
3. Shooting. You can heavily damage tightly-packed units with Artillery.
Fire Bomb Throwers
These guys get their own section because they're pretty unique units. They are very damaging to enemy morale, but they can backfire and kill your own units, or themselves! Best used in Siege Defence or used to rout Ashigaru approaching your lines. Remember to turn Fire At Will off after they move behind your lines or they will kill your own men!
Differences between Samurai, Monks and Ashigaru and Heroes
Warriors trained from birth. High morale, won't break easily and will do alot of damage to the enemy. Yari and Naginata Samurai are Defensive units, due to their high Armour and Defence stats. Katana and No-Dachi Samurai are Offensive, due to their high attack and charge stats. Bow Samurai are superior to Bow Ashigaru due to their higher armour penetration, reload times and accuracy, and the same with Matchlock Samurai.
Peasants drafted to fight for their Daimyo. They have low morale, will break easily and are usually ineffective against Samurai, unless very Experienced. Yari Ashigaru are Defensive, when in Spearwall against a charge of enemies they can kill even Katana Samurai. Bow Ashigaru and Matchlock Ashigaru are decent units, though they have low accuracy and reload times.
Buddhist Warrior Monks. They have better morale than Samurai and rarely, if ever, break. They are usually better than Samurai of the same type. If you convert to Christianity you cannot recruit these awesome units. Their Warcry ability can make Ashigaru flee in seconds, and even Samurai will mellow. Naginata Warrior Monks are good against Cavalry and Infantry, and can usually win in a fight against Katana Samurai. However, they have low armour and are vulnerable to Archers. Bow Monks are better than Samurai in terms of accuracy and reload times, but their armour is terrible and they are vulnerable to archers.
An elite specialist with a few retainers and bodyguards to help him fight. I've never seen these guys break, and they give a morale boost to nearby units. Their small unit can easily take on 5 normal units and do alot of damage, but make sure to use normal units as well, or they will be swamped by heavier numbers.
Generals are very important in Shogun 2 compared to previous Total War games. They have special abilities ranging from Inspire, which significantly buffs a single unit, to Rally, which gives a morale boost to all units within the General's radius. However, by far the best is the ability Stand and Fight. This dismounts your general and leaves him unable to move or use other abilities while in effect, but it gives huge bonuses to all nearby units.
In the early game, your Generals are very important because you will mostly be using Ashigaru, who have pitiful morale. The General's abilities will be invaluable when using Ashigaru. There are a few different Ability Paths a General can go down as he levels up, and I don't want to spoil the RPG element of the game, so I'll leave that up to you to find out!
This is when you have more and better of a certain type of unit than the enemy e.g. Cavalry Superiority. Cavalry Superiority is good, because you can kill off the enemy Cavalry and then Flank and Charge with impunity, and Yari Cavalry can kill two to three units of Cavalry at the same time. Infantry Superiority means you will win a melee with enemy units, so if you have five Katana Samurai and they have three Yari Ashigaru, you will win. Archer Superiority. This means you can kill alot of enemies with your Archers while they cannot kill as many of your own men, and you will win any Archer Duels that occur.
If you have full Superiority in a battle, you will inevitably win. Always go for balanced armies so you can maintain Superiority in all your battles.
I hope this helps people new to Total War get accustomed to battles. And if this doesn't help you, there is always the Tutorials. And remember, practice makes perfect!
Thanks for reading.