Some day in the zombie apocalypse; there will be a large war between zombies and humans. Here are some useful tactics we can employ. (Feel free to make up your own names for the tactics; after all they haven't been created before)

Common Tactics

Quarantine: Seal an area off to prevent further contamination.

Extermination: Kill everything, zombie or not

Evacuation: Take people away from an infected area

Isolation: Isolate the first zombies from any people and kill them

Distraction: Order the army to retreat and allow zombies to kill civilians (ever heard of the Reddeker plan?)

Retreat: Flee an infected area

Charge: Attack an infected city

Marsden:

Extroversion(My own term): Traverse a population out of the cities and into rural areas to slow down the rate of hordes gathering.

Introversion (My own term): Traverse the population to major cities to protect them; thus trying to stop the outbreak.

Alicestar:

Hybridization: trying to create a zombie human hybrid (I know all you guys will be horny but this is not recommended)

hammer & anvil: using a small attack on a horde to lure them to there demise (say a building filled with ANFO)

firefly (sky-flower): using aerial bombs or fireworks to distract the hordes from collection missions (could possibly work)

touch 'N' go: also known as the hit and run or "ghost" technique used by the VC in Vietnam and currently in use by Al-queda forces in south and central America as well as southwest Asia.

"pushing": using high concentrations of fire or explosives to direct and funnel a horde like cattle.

KaikelX:

Lightning Advance: Sweep through a city and quickly dispatch any and all hostiles.

Steady Advance: Exact opposite of Lightning Advance. Take that city one room at a time.

Cactus Advance: Keep the entire force together while clearing the city to reduce casualties.(Hopefully)

Annihilation: Nuke the city. (Not recommended)

Siege War: Use artillery to soften up a city before sending in troops to use an advance tactic. (the buildings would mostly be leveled, reducing the chance of zombies dropping from above.

Sporezombie
Iron wall runner: A wall of gunners with semi-auto weapons line up in 2 rows with the first row on their knee and the second on their knee but their gun in between the tow in front of them. They fire in volleys taking out targets by aiming for the head. Behind the wall are runner who run ammo back and forth giving ammo to the men on the wall. The signal for ammo is a gun sticking out of the wall. There is also a forth man waiting to rush forth and take someones place. A switch happens every hour cycling between the three men.

Steel rain: A turret placed to fire over the heads of iron wall and fires into the horde when given the order it fires in scyle fashion if the wall is being overwhelmed by the numbers it fires three waves back and forth then stops and reloads.

Madman's stand: A armored vehicle is let through the wall and drives through the horde to the middle or the back of it to open fire on the horde from with in the vehicle to divide the horde.


Strike: Get in, kill as much as possible while enemies are confused, identify all hostiles, and get out. Tell the assault team of all hostiles in the area, then wait.

Assault: Just sweep the city. Get in once, killing as much as possible, then do another sweep. Kill all you may have missed, then go back again. Make sure all hostiles are destroyed.

Filter: Like an assault, but with only one sweep. Get into the area and take any survivors, and leave the zacks behind, thus 'filtering' the area. Only use noisy weapons when necessary.

Lure: Use noise, lights, and shiny things to lure a horde to an area where they will be captured, mass murdered, or other.

AZ-Terminator001
Purge v1.0: Have Bulldozers or Combine harvesters or Those mine clearing flail vehicles or any armored vehicle that's wide enough to take up a road and has a dozer blade or big cutter JUST MAKE SURE THAT THERE ARE GUYS WITH FLAMERS OUT FRONT IN A LITTLE HATCH! Position them on the main roads to a zombie infested area. Have dudes with flamers or sharpshooters(or both) take out any Zombies that come behind the vehicle. The front will chew through any that come that way(cutter) or keep them from biting the crew(dozer blade) and burn them to cinders(hence why it is called Purge). Keep on that path until you leave the area. What you do next is your choice.
Purge v1.1: Like purge but with no vehicles. Just a lot of guys with explosives, flamers, shotguns and RPG/Missile Launchers(and CCWs, Lots and LOTS of CCWs).
Oh yeah, AliceStar, the word you're looking for is Guerrilla Warfare

Alicestar: yeah, guerrilla warfare is the CNN term for the above described tactics sorry about that, I guess I have to dumb it down for the halo junkies

Konstantino-Use the 28 Days Later Tactic. NO ONE SURVIVES AT ALL.

master.moxes

The Porcupine: Highly mobile (probably mechanized infantry/tanks) assault elements that can fight/support/run at will. The focus is on creating mobile strongholds to slowly consolidate into territory while repelling any attackers.

tacticalplanner
Hook, line, and sinker: Lure the zombies into a city with no survivors, then trap them within. Then you can kill or leave them alone, effectively removing a few million zombies from immediate worries.
DID (defense in depth): borrow some WW1 tactics. build a bunker system ( you don't have to dig them down) with a short wall made of concrete in between bunkers. Build a second line farther back and higher (might need a hill or to dig down) build a third line. set fencing to dictate safe walkways and put pungi stick drop traps and other traps in the rest of the space. This tactic resulted in the millions killed in World War 1. Make sure the farthest line from the fighting can still kill zeds at a decent range. This way if one line gets overrun, it's not over and some well trained and prepared survivors armed with shotguns can push the zeds out of the first line or keep them from pushing forward. This tactic will prevent a "thin red line" defenses with one line that could be overrun more easily than DID.
Asphyxiation: Construct a wall around a large area even if it isn't secured, so no new zombies arrive to complicate things. (ie. wall off the European continent to prevent African and Asian zombies from arriving. This way you only deal with European zombies).
Take one for the team: (Not recommended unless you are sure) During the counter attack of defense, when a guy or girl gets infected, strap a bomb on them or send them out with a weapon and they fight alone, then when they fall (either eaten or the infection gets them) blow the bomb or recover the weapon some way.

~Jack~:

(Note: These are bold tactics that are only to be used when you KNOW you will come out on top, or no other options appear practical.)

Line Warfare: Most effective in large, open fields, this classic form of warfare was used throughout Europe during the Renaissance and some time after. It's not something you would want to use against other people, but against unarmed zombies, it can be a very effective strategy. Three lines of soldiers with any number of weapons, can lay down enough fire to wipe out any zombie horde coming from the front.Mostly an offensive tactic, It is important that the troops in the formation maintain discipline as they tall take turns shooting and reloading.
This tactic is best used in situations where the zombie horde that is being fought has no chance of attacking the flanks, or attacking from behind. (That is why intelligence is crucial) If the line is breeched, the troops are to retreat and regroup as soon as possible. (Always have a route of retreat)

Palisade Warfare: Light palisades, made from either wood or metal, they are quick and easy to assemble (not to mention portable). Ranging in height from only a few feet and higher (usually 10 feet), it can be an effective and simple barrier to construct. Used mainly for defense, a large force of a few hundred soldiers can set it up in the period of a few hours, and can easily defend themselves from just about any zombie attack. By shooting through the wall, or over it.
It is best used in tandem with forms of "Line Warfare" to protect the troops up front, on the flanks (if there are any), and behind the troops as a whole. If the palisade is breached, the troops are to fall back away from the wall and shoot at the zombies inside.

Mrbob360
Calvary Attack: Light attack vehicles (Trucks with Guns, Jeeps with guns, etc.) Circle the enemy and pepper them with machine gun fire
Walking line: Troops line up and advance slowly firing as they move hopefully taking out any hostiles (Only recommended if the enemy is a slow moving zombie)
Staggered line: Same as above but the troops are staggered instead of standing in a line, (Vehicles could be in the back to provide some cover fire)
Crescent moon: Tactic used by armies back in Greek times, Troops form a crescent moon formation and as the enemy comes into the moon troops circle around and don't offer any escape route.

Andrew1602:
Iron Fist: Get soldiers loaded up with thick armor, heavy automatic weapons, and send them into the city to clear out the Zombies. (Slow tactic)
Ancient War: Load up soldiers with spears and light skin tight clothes, and send them into the city to clear out zombies. (Fast Tatic)
Phoenix: Load up large planes with bombs, grenades, pipe bombs, napalm, and other explosive matierals. Fly the planes over the city and drop the cargo. Return a second time and re-bomb what ever remians. (Use this as a last resort. Not recommended unless all else has failed and the plenty of explosive matter.)