War isn't fair. This is a fact that you become painfully (although less painfully than in real war I imagine) aware of once you get into Warfare 1917. Set in the trenches at the end of WWI you can choose to take control of either the British or the Germans and you must deploy your troops in order to push the enemy back and claim their territory.
As you progress (surprisingly quickly) through the ranks and levels, you are awarded new troops to play with, new barrage weapons to control, and eventually a tank to rumble forward with under your command. Be careful though, as in the heat of battle your troops can be struck with fear should too many of their comrades fall by their side. Your country needs you!
Click on the troop type of your choice and wait until loads, when it will join the battle. Then you can choose another troop - some take longer to reload than others, but all options will reset themselves when you choose a new troop. Click the switch at the bottom of the trench to see the contents of that trench and to choose when to go over the top (only 3 troops per trench).
It might sount complicated, but it's easy once in the game.