*UPDATE MAR 1 2013* – This farming method is no longer reliable since the last map changes and Piranha nerfs. It can still be done, but it is a little harder. An easier way to farm Platinum as of the Reckoning DLC is here: http://girlplaysgame.wordpress.com/2013/03/02/mass-effect-3-the-new-way-to-farm-platinum-on-firebase-glacier-hazard/
Time is money in Mass Effect 3 Multiplayer, literally. Follow these simple steps to beat Platinum in less than 15 minutes. My personal speed record is 11 minutes and 46 seconds, but I would say the average time would be between 15 and 20 minutes.
1. Use a team of heavy hitters.
In my personal opinion, the best four-player setup for this strategy is everyone playing as Geth Infiltrators with Proximity Mines and Hunter Mode fully upgraded for radius and damage. You only need to upgrade Tactical Cloak to level 4, spec’d for damage. Max out for damage in the other categories.
Equip Piranha X (a lower level Piranha is acceptable as long as you buff it with equipment like Shotgun Rail Amp III or IV) with the Smart Choke (+25% Accuracy) and/or increased Piercing/Damage. Use equipment to make up for what you lack (ie. if you went with the Piercing mod on your Piranha, equip Shotgun Rail Amp; alternatively, if you went with Damage mod on the Piranha, equip Armor Piercing Rounds).
I’ve also done this with two Geth Infiltrators and two Soldiers, but it tends to go faster if everyone plays as Geth.
2. Choose the right setup.
Select Firebase Glacier (the smallest map) with Cerberus on Platinum. Choosing Cerberus tends to spawn more Atlases which are slow moving and easier to kill than Primes or Banshees.
3. Run around like a wolfpack!
The key to doing this strategy well is to move as one. Whatever you do, DO NOT CAMP (especially not in that small room where everyone tends to camp). You will run out of ammo and you will die.
Instead, start at the “top” of the map. By having all your team at the “top,” it will ensure that the enemies spawn at the “bottom.” When the enemies spawn, run down to the bottom and kill them all. This should take less than a few seconds, that’s how strong your firepower will be. Then, run to the “top” again where new enemies will have spawned. Continue this cycle, moving together at all times.
The most efficient way to do damage as the Geth Infiltrator using this strategy is to Cloak, throw a Proximity Mine, then shoot like crazy. Repeat often.
4. Be prepared to die.
Fact: as a Geth Infiltrator, you will die. Often. You have to rely on the fact that your team will be there to pick you up and have enough firepower between them to kill what got you down. It really helps to have a microphone.
5. Hope for “easy” objective waves.
Sometimes you will get shitty objectives like Hacks. Don’t be afraid to use a missile or two when the time is right.
And that’s it! You should be able to beat Platinum fairly regularly and easily with this method, provided everyone on the team knows what to do.
If you have any better/faster ways to beat Platinum without cheating, post in the comments or email me!