MGO is quite fun. I'm level 8 in MGO. I'm just trying to get the Foxhound emblem >_>

My tips:

Wall hiding
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One of the great things about MGO is that when you hide behind a wall, (move around by using your R3 button), you will have better sight surrounding everywhere else around that wall, checking if there are enemies or not. Those enemies won't be able to see you.
Since I'm offensive, I usually jump to each wall, making sure there are no enemies, then I move on.

Hiding behind a wall is advantageous. When you hide behind a wall, and there's an enemy going past you, all you gotta do is:

1) Aim for the enemy's head.
2) Then move out of the wall, and shoot his/her head fast. You have better chance of surviving after the kill, since that enemy cannot tell if you were there or not.

When you hide behind a wall, don't use the Triangle function because it's ineffective. If you use the function and shoot an enemy via a wall, there's a good chance that the enemy will see you faster before you move out. Aiming and shooting an enemy while hiding a wall beforehand (without the Triangle function) is much more effective.

Enemy tag
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From my exp, there are a lot of rooms that have this function enabled. This method can be useful as a sniper.

Enemy tag is when your crosshair is on an enemy, his/her tag will display. This is an indicator to show that if you shoot him/her while the tag is still displaying, there's a 99% chance that the enemy will recieve bullet damage from you. Assuming a room has this function enabled, if the tag doesn't display and you shoot, he/she won't recieve bullet damage from you. Why? Because your crosshair is not exactly on the enemy. Basically, use this method when you always aim for head, you aim for head, tag displays, shoot quickly, boom dead! This can be useful as a sniper.

Skills
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While I don't use other skills, I use Narc lvl 3, Monomania lvl 3 and Assault lvl 2. With Monomania lvl 3 and Narc lvl 3 combined can be crazy. This combination allows you to see enemies much better than before. You can also SOP link, so that your team mates will see the enemies' as well.

Buttons and settings
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You should set the sensitivity to 10, don't worry, you will get used to it. This allows you to aim enemies faster.
Change the setting to ''Recall'' for changing items in your L3 and R3, Recall allows you to change faster. Just press L3 or R3 gently, your item will be changed with another item faster.

If an enemy is shooting at you out of no where, just don't stand. The enemy will kill you faster if you stand, so intead, just use your card box or use X (roll) which can evade the bullets, run and hide or whatever.


For me, there is only one disadvantage in MGO which is spawn camping.
It sucks, however, if you're a good player, you shouldn't have any problem killing them. Run to places where there are no enemies in your base, giving you a better chance of not getting killed again. Either do that or just quit the room, simple as that.