Added Storm Cauldron and Rites of Flourishing.

auto=maxplay(land)+1 opponent   --- works!

[card]
name=Rites of Flourishing
auto=maxplay(land)+1 opponent
auto=maxplay(land)+1
auto=@each my draw:draw:1 controller
auto=@each opponent draw:draw:1 opponent
text=At the beginning of each player's draw step, that player draws an additional card. -- Each player may play an additional land on each of his or her turns.
mana={2}{G}
type=Enchantment
[/card]

projects/mtg/bin/Res/sets/primitives/mtg.txt

@@ -51349,6 +51349,16 @@ mana={2}{U}{U}
 type=Sorcery
 [/card]
 [card]
+name=Rites of Flourishing
+auto=maxplay(land)+1 opponent
+auto=maxplay(land)+1
+auto=@each my draw:draw:1 controller
+auto=@each opponent draw:draw:1 opponent
+text=At the beginning of each player's draw step, that player draws an additional card. -- Each player may play an additional land on each of his or her turns.
+mana={2}{G}
+type=Enchantment
+[/card]
+[card]
 name=Rith's Attendant
 auto={1}{S}:Add {R}{G}{W}
 text={1}, Sacrifice Rith's Attendant: Add {R}{G}{W} to your mana pool.
@@ -61509,6 +61519,15 @@ power=1
 toughness=2
 [/card]
 [card]
+name=Storm Cauldron
+auto=maxplay(land)+1 opponent
+auto=maxplay(land)+1
+auto=@tappedformana(land):all(trigger[to]) moveTo(ownerhand)
+text=Each player may play an additional land during each of his or her turns. -- Whenever a land is tapped for mana, return it to its owner's hand.
+mana={5}
+type=Artifact
+[/card]
+[card]
 name=Storm Crow
 abilities=flying
 text=Flying (This creature can't be blocked except by creatures with flying or reach.)