-Equip a member of your party with a Gravity materia, at any level to hit the Emerald Weapon for 9,999 damage. Using this and the Quad-Magic combo can take almost 40,000 hit points from one attack round alone.

-Equip the following materia combination: HP Absorb + Knights Of The Round, W-summon, Mime, Underwater (and nothing else). Use a Hero drink, then summon the Knights Of The Round. Each time he/she will gain over 9,000 HP points. After that, just Mime this attack until the Weapon is defeated. Keep your materia number as low as possible; the more materia equipped, the more the Weapon's Air Tam Stomp will effect the party. For example, if four materia are equipped the Air Tam Stomp will take off 4444 HP points, five materia will result in 5555 HP points and so on.

-Enter the battle against Emerald Weapon with a character equipped with a Gravity materia and all characters with a Reflect Ring. Cast Demi 3 onto your characters with Quadra magic and W-Magic. Since every attack will hit with 9999 damage, a total of about 40,000 damage will be done due to the Quadra Magic. With the W-Magic, it will hit almost 80,000 damage. Finally, because it was cast upon all three of characters and reflected, it will hit Emerald Weapon a total of three times.

-Place Cloud, Red XIII, and Tifa in your party. Get their ultimate weapons and level 4 limit breaks, then build them to level 85 to 90. Equip Knights Of The Round and MP Absorb on Cloud, Phoenix-Final Revive on Red XIII and Full Cure, Comet and some HP pluses on Tifa. Build their limit to full,  run into Emerald Weapon with the submarine, have Cloud use Omnishlash, and every one else use their limit breaks. Cast Knights Of The Round, and if you are low on HP, cast Full Cure. Emerald Weapon has approximately 700,000 HP.

-Go to the forest outside the burnt Mako reactor and fight some Frogs. Use Mini on them and then Manipulate them. Get them to make the last two digits of your life on all characters to "77". However, this life total must be below 7777. Heal yourself so as your life totals on each of your three characters equals 7777. Equip one of your characters with W-Summon and Knights of the Round. Equip everyone with Mime materia. Fight Emerald Weapon, and at the start each character should hit Emerald up for 7777 for a long time. Simply have one character cast Knights of the Round twice and then have the other two characters Mime that. After six Knights of the Round summons, Emerald Weapon be defeated. That way, only one character takes about 6000 damage and nobody else takes any damage.

-When facing the Emerald Weapon, make sure one of your characters has only two materia equiped and has 9999 HP. When Emerald Weapon attacks with it's Air Tam Storm attack (which does 1111 damage for each materia equiped to that character), it will result in 2222 damage to that character, leaving him/her with 7777 HP and the Lucky 7777 bonus.

-Obtain the Final Attack materia from the Battle Arena at Gold Saucer and win the special battle (accessible when Cloud has both the Level 4 Limit Break "Omnislash" and W-Summon materia). Link the Final Attack to the Phoenix summon materia. When that character dies, it will revive him/her and any other fallen allies. This is great for countering Emerald Weapon's attack if it does 9999 damage to all your characters.

-Emerald Weapon has 1,000,000 HP.

-Emerald Weapon's beam attacks are magic based, so if you cast Wall you can cut his beam attacks in half and also reduce the damage from his stomp attacks.

-Use Vincent's third Limit Break (Hellmasker). The Nightmare attack it uses will occasionally cast Stop on Emerald.

-Have Cait Sith with his Slots limit break. Save the game right before you fight him with Cait Sith's limit bar full. Start the battle and use the Slots limit break until it ends up with something that resembles Cait Sith. Use it on Emerald Weapon to defeat it with one hit.

-First, equip the best of all equipment that you have. It doesn't matter if you can get AP with it or not. Also equip an HP Plus Materia to each of your characters so that you have 9999 HP on them, then equip some sort of curing Materia to each one. Note: Only equip one of each. When the battle starts, use lots of defense and all the curing spells you need. Just survive for awhile with your Limit Breaks. Eventually, Emerald Weapon will attack with a skill that does 1111 damage for each piece of Materia you have equipped. When this happens because your party was at full HP when they will now have 7777 HP and will be able to do the lucky sevens attacks.

-The Underwater Materia, Mime, Knights Of The Round, HP Absorb and a couple Mastered HP Plus (as many as needed to get 9m999 HP) are required. On one character, put Mime and all the HP Plus. On another character, put Knights Of The Round and in an attached slot, put HP Absorb. On your finalcharacter, put the Underwater Materia. Start with Knights Of The Round, then Mime it for the remainder of the fight. Make sure that the character with Mime does not have more then five Materias equipped because Emerald has an attack that deals 1111 times the amount of Materia, it is usually used right after another attack. Using Knights of the Round with HP Absorb should allow your character to heal about 8,000 HP each time he or she uses it. Simply continue miming and make sure never to use other attacks and this fight should be easy. Afterwards, bring the Earth Harp to the man in Kalm to receive a full set of Master Materia.

-Notice that as your health deteriorates, so does the attack power of the Cloud's blade. Use Gravity + Elemental Materia both at Master on your weapon to remedy that, as even if your health is low you can still do a hefty chunk of damage as well. Revive + Final Attack, and the enemy skills Angel Whisper, White Wind, and Big Guard are also useful, as well as Knights Of The Round and Counter Magic. Keep hammering away until he dies (this is all assuming you have the Underwater Materia).

Use the following trick to get All 7's Fever for the battle. It requires 9999 max HP. Have the character to get All 7's Fever equip only two Materias. One must be HP Plus and other is your choice. Fight Emerald Weapon. When you do enough damage to it (when his emeralds shut down), it will start using Aire Tam Storm which does 1111 damage for each Materia on character. Your character should now have All 7's Fever. Note: This can be done for all characters, but the effect is not cumulative.

-Note: This trick requires quite a lot of patience and luck. First, have the following: Underwater (Independent), HP Absorb (Support), Knights of The Round (level 2 or higher), HP Plus (Mastered), Mime (Command), Counter (Support-- not Counter Attack), and W-Summon (Command). Link Knights of the Round to HP Absorb and Mime to Counter. Hopefully your HP is above 5000 at this point (being at level 60 or higher is recommended). Ride your Highwind to Junon and get into a random battle. Kill two of your characters, leaving the one with the highest Magic Attack stats. Equip a Mystile and Sprint Shoes to him or her. Take your submarine underwater, then look around and you should see Emerald Weapon either standing in a crater, in a seaweed garden, or moving around. If you cannot find it anywhere, go back up to the surface and submerge underwater once more. Collide the sub into Emerald Weapon and the battle will begin. With the Sprint Shoes, your character will always be in Haste. However, Emerald Weapon will always attack first. Your "wait" gauge will still be filling while it is attacking. Select W-Summon and choose Knights Of The Round both times. When Emerald Weapon hits you, a bar at the top of the screen will say " has made a useless imitation". This means that your that Counter/Mime is working. As your character is casting Knights Of The Round, it will appear as if he or she is casting it four times instead of two. Also, Knights Of The Round will restore your HP, because of the linked HP absorb to Knights Of The Round. However, do not just wait for Emerald to attack. When the Summon sequence(s) are finished, allow your wait gauge to fill and select Mime. Emerald Weapon will hit you again, making you cast Knights Of The Round two times, due to Miming the W-Summon you had made earlier in the battle. Also, your Mime will work, casting Knights Of The Round two more times. When Emerald's "eyes" open, it will execute an attack called "Emerald Beam". It hits you, causing you to counter, casting Mime, which you are actually casting Knights Of The Round again, for a total of four more summons. However, Emerald Weapon will interrupt your summon sequences by countering with Revenge Stamp, which will hurt your HP by a bit less than half. Emerald will also execute an attack called "Aire Tam Storm". You should have at least seven Materia Orbs on your Weapon/Armor. This attack will inflict at least 7777 damage to your HP, possibly killing you. However, there is a 33% chance that this attack can miss. To help, tap L1 + R1. If the attack misses, the eyes will die and you will continue to cast Knights Of The Round until either it stops or Emerald Weapons dies.

-First, equip Cloud with a weapon and armor that gives him maximum Materia capability, although they must be linked. Then, fill all of the Materia slots with a Counter Materia linked to a Mime Materia. After that, build up Cloud's Limit Break and go to battle Emerald Weapon. Use a character other than Cloud to give him a Hero Potion. Use Cloud's Omnislash and wait until he gets hit. This will result in Cloud counter-attacking with his Limit Break for a number of times equal to the number of Materia you put the Counter Materia on him. For faster results, you may use Barrett.

-There is a glitch known as "Overflow". There are two weapons in the game that can attain Overflow damage and are capable of killing Emerald Weapon with one hit. This is possible on the North American and Japanese versions of the game on the PlayStation.

Vincent: Death Penalty
When using Vincent's Death Penalty weapon, damage is calculated by how many enemies Vincent has killed. If you kill over 20,000 enemies (this will take a very long time), he will one-hit-kill Emerald Weapon.

Barret: Missing Score:
While using Barret's Missing Score weapon, damage is calculated by how much AP is in the Materia in his weapon's eight open slots. The minimum AP to make this trick work is around 2.75 million AP. Three to four Master Knights Of The Round are needed, as well as Master W-Magic, W-Summon, W-Item, Typoon, or Bahamut Zero. Knights Of The Round has 500,000 AP when mastered and all the others have 250,000 AP when mastered. When you have over 2.5 million AP in Barret's Missing Score weapon, engage Emerald Weapon. First, you need to use four Hero Drinks on Barret (to double his attack strength), then use Berserk magic on Barret (again, doubling his damage).

Using either method, the damage done on Emerald weapon will say anything from 1 to 9999 or even letters and symbols.