  The $\Phi^4_3$ equation is a singular stochastic PDE with important
applications in mathematical physics. Its solution usually requires advanced
mathematical theories like regularity structures or paracontrolled
distributions, and even local well-posedness is highly nontrivial. Here we
propose a multiplicative transformation to reduce the periodic $\Phi^4_3$
equation to a well-posed random PDE. This leads to a simple and elementary
proof of global well-posedness, which only relies on Schauder estimates, the
maximum principle, and basic estimates for paraproducts, and in particular does
not need regularity structures or paracontrolled distributions.
