What was used for protection in the trenches in world war 1?

In World War I, soldiers in the trenches used sandbags, wooden planks, and barbed wire for protection against enemy fire. The trenches themselves were often reinforced with earth and wood to create a defensive barrier. Additionally, soldiers utilized dugouts, which were deeper shelters within the trenches, to shield themselves from artillery and sniper fire. These measures helped to mitigate the dangers of the brutal warfare that characterized the conflict.