What prevents bullets striking a solder's chest he is on the trench board?

Soldiers in trenches often use protective gear such as body armor, which can absorb or deflect bullets. Additionally, the design of trench systems can provide natural cover, as the earthworks help shield soldiers from incoming fire. The position and angle of the soldier in relation to the firing line also play a crucial role in minimizing exposure to bullets. Lastly, the use of trench boards elevates soldiers slightly above the ground, which can help reduce the likelihood of being hit by low-trajectory shots.