The Light Soldier is from the original game, The Conquerors. It is the first unit to be seen in the game along with the Construction Soldier (water maps and territory mode only) and Command Center. In Conquest, Survival, and King of the Hill games, you are given 3 light soldiers and a Scout to work with at the beginning.
Light soldiers are plastic textured with a red head and torso with white limbs. They wield an M4 Carbine.
In the beginning of the game, a light soldier is mostly used for claiming Power Plants or Nuclear Plants due to them being three of the 4 or 5 units spawned in the game. They don't fire as fast as a Heavy Soldier and usually aren't used for raids. Later on in the game, it is rare to see a light soldier. According to the help guide in the game, it is recommended to use a mixture of light and heavy soldiers, though this is often ignored.
It's not a good idea to raid people with even 10 light soldiers as they do a minimal amount of damage to anything. Later on, as the game progresses, you could follow what the creator said and do a mix up with the soldiers to have a better attack.
Despite official recommendations, many people heavily recommend to never use light soldiers, aside from using them to build plants during the beginning of the game. Instead, they recommend only using Heavy Soldiers. While heavy soldiers cost twice as much, they are still cheap and seem vastly more powerful. Even a mix of both light and heavy soldiers is criticized; a force of just heavy soldiers is said to be the best way to go. The one exception where light soldiers are superior are when they're used as meat shields for Explosive Tanks. The light soldier is cheaper and has the speed to keep up with explosive tanks, where heavy soldiers fall behind.
- Like Heavy Soldiers, they are armed with M4 Carbines, the standard weapon for US infantry.