Without my first two, if you know how to use me, I point the way. As a whole, I envelop a certain area, so to say.

All around you I shall rest To protect your noble crest; From banners high to dungeons low, I prevent your overthrow. If a Gatherer Magician you might be, Only by air you may pass through me!

A trapping of compounds close to the surface, Or a reaction of compounds in sunlight can curse us. Either way, it’s harder to breathe or see, Sadly common in cities; can you guess me?

A silent guide to paths unknown, where names and numbers intertwine like roads on a map, leading you to hidden places.

I am a shout, a sharp sound In American football, better get ready In the military, better pay attention I am also a humble house For the indigenous, traditional For the nomad, temporary What am I?