Keep an eye on left side by Ink Grenades one or two enemies pop up in there. 40-50 go for the higher ground up by Oneshot and Mulcher spawns.

The Formers can easily overtake an ally especially with the large numbers that spawn, the same goes Polyps. Waves 31-40 split between using Retro Lancers and Lancers. Try and keep up the Fortifications as well. Save your cash for the Silverbacks on waves 10, 20, 30, 40, and 50. Chainsaw kills get you a nice chunk of change and conserve ammo, plus it's a great way to keep grubs at bay. Hammerburst Rifles and Snub Pistols make great weapons to use while at the top as their range and accuracy will be enough to down enemies nearly anywhere on the map. This is not only a great tool to get people out of the Hill, but also to keep them from reaching the hill when you are positioned at the top. A Digger Launcher pops just before climbing up the hill to the power position. Keeping an eye on the deck under the crane proves useful as enemies caught in this location make easy target to take out. Gnasher Shotguns and Sawed-Offs do exceptionally well on this map due to close quarter areas and the overall size of the map which is relatively small. The rest of the teammates will scramble to either the crane which is equipped with the Hammer of Dawn or the Mortar, or they will try to secure the hill, which will secure your team the Oneshot. Right off the bat it's a good time to throw it across to the enemies grenade spawn as they are likely doing the same thing you are.

The start of the match will usually be greeted by teammates scrambling for the Ink/ Incendiary Grenade position. The Oneshot also pops here making it even more of a priority to secure. A few soldiers will want to secure the high ground up the hill though as this is a power position. The bulk of the action will take place near, or around the crane in the center of the map. Trenches is a symmetrical map meaning both teams having the same ground layouts. The map Trenches is available in all three of Gears of War 3's Multiplayer modes.

Gears of war 3 maps list