To survive in Electronic Arts' latest third-person shooter for the Xbox 360 and PS3, Army of Two, players not only have to think in terms of cooperative play - they also have to take the element known as Aggro into consideration. We get a crash course on just what Aggro is in this trailer video of the game that hearkens back to the days of beautiful, synchronized co-op.

So what is Aggro, anyway? Aggro is the game's way of measuring just how much attention the enemy is paying to you or your partner. Naturally, the less Aggro you have, the less shots you'll take, and the more you can walk around killing people like an unseen ninja.

Simply put, whoever has the bigger gun between you and your partner will be the one getting pounded with enemy fire. With the use of the onscreen Aggro meter, players can use this to their advantage.

Get yourself up to speed by the embed below. Enjoy the video!