Gaseous form is a slang term used by Magic R&D to describe the effect that creatures neither deal nor receive damage. Based on the eponymous Gaseous Form, the effect was later moved from primary blue to primary white (Ghostly Possession) and secondary blue. In the very early days it has also showed up in green as a Fog variant. White will grant the ability to creatures, whereas blue tends to have the ability on creatures. It was also featured as a loyalty ability on Kiora, the Crashing Wave.
- Mark Rosewater (June 5, 2017). "Mechanical Color Pie 2017". magicthegathering.com. Wizards of the Coast.
- Mark Rosewater (December 25, 2013). "Couldn't all of Kiora's ability be on a mono-green Planeswalker?". Blogatog. Tumblr.
- Mark Rosewater (January 24, 2014). "Why didn't you reprint Gaseous Form to hint at Kiora's + ability being Blue?". Blogatog. Tumblr.