Bacterial pathogens are facing fierce conditions to colonize their host and launch successful infections. Not only they have to escape the immune system but they should also compete with other invading organisms or resident bacterial flora. This warfare is crucial for winning access to sometime scarce resources such as iron or other essential nutriments which will sustain growth and survival. These pathogens employ a variety of strategies which are associated with canonical lifestyles. Here we will discuss how Pseudomonas aeruginosa uses a bacterial weapon called the type VI secretion system (T6SS) to eliminate competitors. There are multi examples of bacterial toxins, which are transported in a T6SS-dependent manner, and P. aeruginosa can use a remarkable collection of ammunitions, which make it a resilient and potent competitor when facing other organisms. We will discuss the kind of T6SS toxins that are injected into bacterial preys and how they can point at the identification of new antimicrobial targets which could be used for drug development