Volatiles play a critical role in the generation, evolution, and eruptive style of magmas. Information about the behavior of volatiles in the subsurface can be gleaned from laboratory experiments and modeling as well as petrologic and textural examination of minerals, vesicles, melt inclusions, and fluid inclusions in erupted products. During both eruptive and quiescent periods, outgassing at the surface is often assessed using a combination of direct gas sampling, in situ sensors, and remote spectroscopic methods. Independently, each of these techniques can provide important insights into volatile behavior. However, integrating petrologic methods and surficial gas measurements will promote an improved, more holistic understanding of volatile dynamics throughout volcanic systems. We seek contributions that combine a variety of techniques for evaluating the behavior of volatiles during magma ascent, degassing, and outgassing/eruption. We particularly encourage contributions that leverage both petrologic and surface gas measurements to reconstruct volatile behavior.