This'll teach you how 2 make a very strong, protective, & useful bunker! I addition, you'll have yourself a trench.

Step 1: Needed Supplies:

This is a more expensive project if you don't own certain things. You'll need:
1. four to eight boards.
2. a shovel.
3. if living in a rocky area, maybe a pick axe or gunpowder.
4. a wooden plate that would cover up part of your trench
5. about nine bricks.
6. cardboard boxes.
7. Sometimes a whellbarrow.

Step 2: Starting Out

You'll need to find a place to dig a trench. Dig a big enough trench so that numerous of your team mates could get in it. Pile up the dirt in front of your trench. This'll mean you don't have to dig down so deep. If you want to dig many trenches connected together (you'd need to dig at least two trenches in parrellel with eachother, with at least one, shorter trench connecting the two) then put the dirt in a wheelbarrow and keep it there. When you do your trench that's in front, put all the dirt in front of that. Or you could do your forward trench first.
If you hit any rock, you can break through with a pick axe or gunpowder.

Step 3: Wrapping Up

Okay, good, you're done.... With the first part. Now, lay three brick towers three bricks high so two would be at either end of your wooden plate, with one in the middle. Now, lay your board down so the bricks lavate your board, with the other side laying down on the ground. It should go across your trench. Now, you can poke your barrel out of the openings provided by bricks and shoot at the enemy wuth good cover. If you made a complex trench system, the best place to set one is both, in the front and in the back. In the front, you have cover for surprise attacks. In the rear, it offers a good last-ditch position if the enmey has captured your other trenches. If you can, make both. You can also make more than one per trench.

Step 4: Last Steps

in front of your fire trench, take your boards and lay half of them down on the ground, half-buried. Take the others and stand them up, and bury it haf-way. This is optional, and doesn't cope very well with tall dirt mounds. Take cardboard boxes and fill them with rocks and put them in the back of your trenches, or you can make a smaller entrance into your bunker by stacking them up so you have a nice, wide, trench, but a small entrance. This means that the enemy would have a harder job trying to shoot you inside the trench. In the back, they'll protect you from shots fired from the rear, say your enemy flanks your rear, and can help you from fragmentation from the rear, if a grenade is thrown. Simple, fast, and easy.