Zones are basically lingering area of effects. Most of the zones I see in the PHB last until the end of the encounter. A wall isn't necessarily a zone, it has more in common with a blast or burst effect. Most walls seem to last only as long as they are maintained.Not much summoning before level 3... and would be VERY easy to build one that ignored summoning. Wasn't expecting that, but it seems on par with Fighter stances. I wonder if there will be a single summon maximum and how other things might work - do they count as allies in every sense of the word?
Why is "Wall of Light" not a zone? Maybe I'm misunderstanding what the zone keyword is supposed to represent.
Something else that occurs to me. This class isn't as... well, it doesn't have any real "Wow" that the Druid and Wizard does. The druid has flexibility and finesse, the Wizard has cantrips and choice of dailies. This is rather vanilla, as class designs go.
You mean like Stinking Cloud, which is 'sustain minor' but still is a zone?Zones are basically lingering area of effects. Most of the zones I see in the PHB last until the end of the encounter. A wall isn't necessarily a zone, it has more in common with a blast or burst effect. Most walls seem to last only as long as they are maintained.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.