Mana Web 
Artifact
$18.78 #11551 1.39 29.2 years
Whenever a land an opponent controls is tapped for mana, tap all lands that player controls that could produce any type of mana that land could produce.
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Cards similar to Mana Web expected a card that isn't here?
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War's Toll80%
$9.87↓#5350↑1.25↓20.3 years↓
"Whenever an opponent taps a land for mana, tap all lands that player controls."
Gulf Squid80%
$0.15↓#27248↓0.46↓26.3 years↓
"When this creature enters, tap all lands target player controls."
Rishadan Dockhand76%
$0.23↓#17356↓0.19↓5.3 years↓
"
, 
: Tap target land."
, : Tap target land."
Radha, Coalition Warlord74%
$0.08↓#18693↓0.69↓4.0 years↓
"Whenever this card becomes tapped, another target creature you control gets +X/+X until end of turn, where X is the number of basic land types among lands you control."
Rishadan Port73%
$8.65↓#14580↓0.41↓26.9 years↓
", : Tap target land."
, : Tap target land."
Vernal Bloom72%
$4.17↓#107480.31↓27.9 years↓
"Whenever a Forest is tapped for mana, its controller adds an additional 
."
."
Tectonic Instability72%
$3.63↓#14120↓1.3525.9 years↓
"Whenever a land enters, tap all lands its controller controls."
Wolfwillow Haven72%
$0.24↓#4907↑0.14↓6.6 years↓
"Whenever enchanted land is tapped for mana, its controller adds an additional ."
."
Market Festival72%
$0.17↓#104680.46↓12.3 years↓
"Whenever enchanted land is tapped for mana, its controller adds an additional two mana in any combination of colors."
Dawn's Reflection72%
$0.22↓#8972↑0.22↓22.3 years↓
"Whenever enchanted land is tapped for mana, its controller adds an additional two mana in any combination of colors."
Wanderbrine Preacher72%
$0.16↓#17988↓0.00↓0.6 years↓
"Whenever this creature becomes tapped, you gain 2 life."
Overgrowth71%
$0.24↓#3075↑0.22↓28.5 years
"Whenever enchanted land is tapped for mana, its controller adds an additional ."
."
Early Frost71%
$0.12↓#25246↓0.82↓22.3 years↓
"Tap up to three target lands."
Wild Growth70%
$0.35↓#212↑0.16↓33.1 years↑
"Whenever enchanted land is tapped for mana, its controller adds an additional ."
."
Verdant Haven70%
$0.05↓#125470.00↓13.6 years↓
"Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color."
Renegade Wheelsmith70%
$0.17↓#17928↓0.12↓9.6 years↓
"Whenever this creature becomes tapped, target creature can't block this turn."
Vampire Envoy70%
$0.11↓#18914↓0.31↓10.6 years↓
"Whenever this creature becomes tapped, you gain 1 life."
Roots of Life70%
$0.35↓#20228↓0.06↓29.9 years
"Whenever a land of the chosen type an opponent controls becomes tapped, you gain 1 life."
Veteran of the Depths70%
$0.18↓#24938↓0.29↓18.9 years↓
"Whenever this creature becomes tapped, you may put a +1/+1 counter on it."
Fertile Ground70%
$0.27↓#1065↑0.15↓27.9 years↓
"Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color."