Mana Web 
Artifact
$18.07 #11750 1.64 29.4 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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Reports become test cases the matcher is graded against before an update ships. Delvefall isn't a chatbot guessing, it compares the printed rules text of every card with plain math, and examples like yours decide which differences should count.
War's Toll80%
$11.45↓#5443↑1.45↓20.5 years↓
"Whenever an opponent taps a land for mana, tap all lands that player controls."
Gulf Squid80%
$0.14↓#27581↓0.50↓26.4 years↓
"When this creature enters, tap all lands target player controls."
Rishadan Dockhand76%
$0.22↓#17696↓0.12↓5.5 years↓
"
, 
: Tap target land."
, : Tap target land."
Radha, Coalition Warlord74%
$0.08↓#19074↓0.06↓4.1 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 Port74%
$7.27↓#14696↓0.41↓27.0 years↓
", : Tap target land."
, : Tap target land."
Market Festival72%
$0.22↓#106380.33↓12.5 years↓
"Whenever enchanted land is tapped for mana, its controller adds an additional two mana in any combination of colors."
Dawn's Reflection72%
$0.20↓#9146↑0.33↓22.4 years↓
"Whenever enchanted land is tapped for mana, its controller adds an additional two mana in any combination of colors."
Tectonic Instability72%
$3.76↓#14399↓1.50↓26.0 years↓
"Whenever a land enters, tap all lands its controller controls."
Wolfwillow Haven72%
$0.18↓#4995↑0.00↓6.7 years↓
"Whenever enchanted land is tapped for mana, its controller adds an additional 
."
."
Wanderbrine Preacher72%
$0.17↓#17799↓0.12↓0.7 years↓
"Whenever this creature becomes tapped, you gain 2 life."
Overgrowth71%
$0.25↓#3164↑0.04↓28.6 years
"Whenever enchanted land is tapped for mana, its controller adds an additional ."
."
Early Frost71%
$0.13↓#25566↓0.59↓22.4 years↓
"Tap up to three target lands."
Wild Growth70%
$0.40↓#216↑0.16↓33.2 years↑
"Whenever enchanted land is tapped for mana, its controller adds an additional ."
."
Verdant Haven70%
$0.05↓#127270.00↓13.7 years↓
"Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color."
Renegade Wheelsmith70%
$0.18↓#18246↓0.00↓9.7 years↓
"Whenever this creature becomes tapped, target creature can't block this turn."
Veteran of the Depths70%
$0.20↓#25344↓0.05↓19.0 years↓
"Whenever this creature becomes tapped, you may put a +1/+1 counter on it."
Vampire Envoy70%
$0.12↓#19223↓0.00↓10.7 years↓
"Whenever this creature becomes tapped, you gain 1 life."
Vernal Bloom70%
$4.27↓#109570.35↓28.0 years↓
"Whenever a Forest is tapped for mana, its controller adds an additional ."
."
Tale of Katara and Toph70%
$2.03↓#5850↑0.20↓0.9 years↓
"Creatures you control have "Whenever this creature becomes tapped for the first time during each of your turns, put a +1/+1 counter on it.""
Roots of Life70%
$0.33↓#20407↓0.35↓30.0 years
"Whenever a land of the chosen type an opponent controls becomes tapped, you gain 1 life."