An Engineer is an anti-tank soldier. His main duty is to destroy enemy tanks or repair friendly ones. Due to the many different tools an Engineer can carry, sometimes this is not always possible. Engineers come standard with a repair tool and RPG or SMAW.
Rockets can be used against more than tanks. They can be used against infantry, though most players frown upon this. The choice is yours. Those rockets can be replaced by a Stinger, Igla, or Javelin. The stingers and iglas are used by locking on to air vehicles and firing. These are not as strong as javelins, but have a greater range. This will be nerfed in the upcoming patch. Javelins also have the lock on ability for both air and land vehicles. Javelin’s have a short range however, but can lock on to any vehicle that is laser designated and have a dramatically higher damage rate.
Repairs tools can damage or repair vehicles. If a friendly’s vehicle needs repairs the vehicle will light up on the mini map with a wrench symbol. You can also request repairs from an Engineer. Repair tools can be replaced by AT Mines or an EOD Bot. An EOD Bot is basically a mobile repair tool. You can drive the vehicle across the map to repair or destroy vehicles. They can also arm or defuse MCOMs in Rush mode. These EOD Bots can be hard to maneuver if the surface is not flat, and can be destroyed easily by small arms fire. AT Mines are used by placing them on the ground, destroying vehicles as they go over them. You can deploy a maximum of 6 mines at any time. Once deployed they will remain until triggered. Friendly mines are shown on the map as blue, however you can spot enemy mines so they show up as red on the mini map. These will eventually disappear off the map, so it’s recommended to destroy them so your team does not detonate them. An Engineer can also pick up enemy mines even if you do not have them equipped.