English: Schematic phase diagrams for: (A) simple and symmetric complex coacervates with coexistence between a saturated dilute phase and a concentrated droplet phase. Condensation from the red cross can be induced by increasing the concentration (delta c) or lowering the temperature (delta T), or salt concentration. Frequently, only the low-concentration branch of the binodal, or coexistence curve is shown. (B) Non-symmetric complex coacervates. Condensation can be induced by increasing the concentration of A, or reducing the concentration of B. (C) Cross-section through the two-phase region in (B) for varying mixing ratio, highlighting the re-entrant phase transition from one phase, via soluble complexes to two phases and back to one phase. (D) Control over coacervation by reversible post-translational modifications, like in Ddx4 and G3BP1. (E) RNA-dependent coacervation in FIB-1. (F) Effect of RNA on the density and viscosity of the coacervate phase of LAF-1.^[1]