Case of the Locked Hothouse

You may play an additional land on each of your turns.
To solve — You control seven or more lands. (If unsolved, solve at the beginning of your end step.)
Solved — You may look at the top card of your library any time, and you may play lands and cast creature and enchantment spells from the top of your library.

Dunes of the Dead

{T}: Add {C}.
When this land is put into a graveyard from the battlefield, create a 2/2 black Zombie creature token.

Taiga

Sunscorched Desert

When this land enters, it deals 1 damage to target player or planeswalker.
{T}: Add {C}.

Anointed Procession

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Lazotep Quarry

{T}: Add {C}.
{T}, Sacrifice a creature: Add one mana of any color.
{X}{2}, {T}, Sacrifice a Desert: Exile target creature card with mana value X from your graveyard. Create a token that's a copy of it, except it's a 4/4 black Zombie. Activate only as a sorcery.

Spelunking

When this enchantment enters, draw a card, then you may put a land card from your hand onto the battlefield. If you put a Cave onto the battlefield this way, you gain 4 life.
Lands you control enter untapped.

Mayael's Aria

At the beginning of your upkeep, put a +1/+1 counter on each creature you control if you control a creature with power 5 or greater. Then you gain 10 life if you control a creature with power 10 or greater. Then you win the game if you control a creature with power 20 or greater.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Rupture Spire

This land enters tapped.
When this land enters, sacrifice it unless you pay {1}.
{T}: Add one mana of any color.

Hazezon, Shaper of Sand

Desertwalk (This creature can't be blocked as long as defending player controls a Desert.)
You may play Desert lands from your graveyard.
Whenever a Desert you control enters, create two 1/1 red, green, and white Sand Warrior creature tokens.

Azusa, Lost but Seeking

You may play two additional lands on each of your turns.

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Ouroboroid

At the beginning of combat on your turn, put X +1/+1 counters on each creature you control, where X is this creature's power.

Scapeshift

Sacrifice any number of lands. Search your library for up to that many land cards, put them onto the battlefield tapped, then shuffle.

Exalted Sunborn

Flying, lifelink
If one or more tokens would be created under your control, twice that many of those tokens are created instead.
Warp {1}{W} (You may cast this card from your hand for its warp cost. Exile this creature at the beginning of the next end step, then you may cast it from exile on a later turn.)

Mirage Mesa

This land enters tapped. As it enters, choose a color.
{T}: Add one mana of the chosen color.

Plaza of Heroes

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a legendary spell.
{T}: Add one mana of any color among legendary permanents you control.
{3}, {T}, Exile this land: Target legendary creature gains hexproof and indestructible until end of turn.

Cactus Preserve

This land enters tapped.
{T}: Add one mana of any type that a land you control could produce.
{3}: Until end of turn, this land becomes an X/X green Plant creature with reach, where X is the greatest mana value among your commanders. It's still a land.

Plateau

Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

City on Fire

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
If a source you control would deal damage to a permanent or player, it deals triple that damage instead.

Painted Bluffs

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Scavenger Grounds

{T}: Add {C}.
{2}, {T}, Sacrifice a Desert: Exile all graveyards.

Knotvine Mystic

Chromatic Orrery

You may spend mana as though it were mana of any color.
{T}: Add {C}{C}{C}{C}{C}.
{5}, {T}: Draw a card for each color among permanents you control.

Flashback

Target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost. (You may cast that card from your graveyard for its flashback cost. Then exile it.)

Vandalblast

Destroy target artifact you don't control.
Overload {4}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Collective Inferno

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
As this enchantment enters, choose a creature type.
Double all damage that sources you control of the chosen type would deal.

Stomping Ground

({T}: Add {R} or {G}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Hashep Oasis

{T}: Add {C}.
{T}, Pay 1 life: Add {G}.
{1}{G}{G}, {T}, Sacrifice a Desert: Target creature gets +3/+3 until end of turn. Activate only as a sorcery.

Cradle of the Accursed

{T}: Add {C}.
{3}, {T}, Sacrifice this land: Create a 2/2 black Zombie creature token. Activate only as a sorcery.

Worldly Tutor

Search your library for a creature card, reveal it, then shuffle and put the card on top.

Incandescent Aria

Incandescent Aria deals 3 damage to each nontoken creature.

Mirari's Wake

Creatures you control get +1/+1.
Whenever you tap a land for mana, add one mana of any type that land produced.

Hostile Desert

{T}: Add {C}.
{2}, Exile a land card from your graveyard: This land becomes a 3/4 Elemental creature until end of turn. It's still a land.

Prava of the Steel Legion

During your turn, creature tokens you control get +1/+4.
{3}{W}: Create a 1/1 white Soldier creature token.
Partner (You can have two commanders if both have partner.)

Jetmir's Garden

({T}: Add {R}, {G}, or {W}.)
This land enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Titanic Ultimatum

Until end of turn, creatures you control get +5/+5 and gain first strike, trample, and lifelink.

Rith's Grove

When this land enters, sacrifice it unless you return a non-Lair land you control to its owner's hand.
{T}: Add {R}, {G}, or {W}.

Druid Class

(Gain the next level as a sorcery to add its ability.)
Landfall — Whenever a land you control enters, you gain 1 life.
{2}{G}: Level 2
You may play an additional land on each of your turns.
{4}{G}: Level 3
When this Class becomes level 3, target land you control becomes a creature with haste and "This creature's power and toughness are each equal to the number of lands you control." It's still a land.

Grasping Dunes

{T}: Add {C}.
{1}, {T}, Sacrifice this land: Put a -1/-1 counter on target creature. Activate only as a sorcery.

Mondrak, Glory Dominus

If one or more tokens would be created under your control, twice that many of those tokens are created instead.
{1}{W/P}{W/P}, Sacrifice two other artifacts and/or creatures: Put an indestructible counter on Mondrak. ({W/P} can be paid with either {W} or 2 life.)

Leyline of the Meek

If this card is in your opening hand, you may begin the game with it on the battlefield.
Creature tokens get +1/+1.

Mycosynth Lattice

All permanents are artifacts in addition to their other types.
All cards that aren't on the battlefield, spells, and permanents are colorless.
Players may spend mana as though it were mana of any color.

Survivors' Encampment

{T}: Add {C}.
{T}, Tap an untapped creature you control: Add one mana of any color.

Bloom Tender

Vivid — {T}: For each color among permanents you control, add one mana of that color.

Ancient Greenwarden

Reach (This creature can block creatures with flying.)
You may play lands from your graveyard.
If a land entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Thespian's Stage

{T}: Add {C}.
{2}, {T}: This land becomes a copy of target land, except it has this ability.

Harmonize

Tectonic Split

As an additional cost to cast this spell, sacrifice half the lands you control, rounded up.
Hexproof
Lands you control have "{T}: Add three mana of any one color."

Burgeoning

Whenever an opponent plays a land, you may put a land card from your hand onto the battlefield.

Sandstorm Verge

{T}: Add {C}.
{3}, {T}: Target creature can't block this turn. Activate only as a sorcery.

Trace of Abundance

Enchant land
Enchanted land has shroud. (It can't be the target of spells or abilities.)
Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color.

Desert of the Indomitable

This land enters tapped.
{T}: Add {G}.
Cycling {1}{G} ({1}{G}, Discard this card: Draw a card.)

Mirage Mirror

{2}: This artifact becomes a copy of target artifact, creature, enchantment, or land until end of turn.

Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

Exploration

You may play an additional land on each of your turns.

Jungle Shrine

This land enters tapped.
{T}: Add {R}, {G}, or {W}.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Aggravated Assault

{3}{R}{R}: Untap all creatures you control. After this main phase, there is an additional combat phase followed by an additional main phase. Activate only as a sorcery.

Desert

{T}: Add {C}.
{T}: This land deals 1 damage to target attacking creature. Activate only during the end of combat step.

Temple of Civilization

(Transforms from Ojer Taq, Deepest Foundation.)
{T}: Add {W}.
{2}{W}, {T}: Transform this land. Activate only if you attacked with three or more creatures this turn and only as a sorcery.

Ojer Taq, Deepest Foundation

Vigilance
If one or more creature tokens would be created under your control, three times that many of those tokens are created instead.
When Ojer Taq dies, return it to the battlefield tapped and transformed under its owner's control.

Ojer Taq, Deepest Foundation // Temple of Civilization

Abraded Bluffs

This land enters tapped.
When this land enters, it deals 1 damage to target opponent.
{T}: Add {R} or {W}.

Ramunap Ruins

{T}: Add {C}.
{T}, Pay 1 life: Add {R}.
{2}{R}{R}, {T}, Sacrifice a Desert: This land deals 2 damage to each opponent.

Command Tower

Enlightened Tutor

Search your library for an artifact or enchantment card, reveal it, then shuffle and put that card on top.

Ghired, Mirror of the Wilds

Haste
Nontoken creatures you control have "{T}: Create a token that's a copy of target token you control that entered this turn."

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Shefet Dunes

{T}: Add {C}.
{T}, Pay 1 life: Add {W}.
{2}{W}{W}, {T}, Sacrifice a Desert: Creatures you control get +1/+1 until end of turn. Activate only as a sorcery.

Toph, the First Metalbender

Nontoken artifacts you control are lands in addition to their other types. (They don't gain the ability to {T} for mana.)
At the beginning of your end step, earthbend 2. (Target land you control becomes a 0/0 creature with haste that's still a land. Put two +1/+1 counters on it. When it dies or is exiled, return it to the battlefield tapped.)

Mana Reflection

If you tap a permanent for mana, it produces twice as much of that mana instead.

Conduit Pylons

When this land enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Akroma's Memorial

Creatures you control have flying, first strike, vigilance, trample, haste, and protection from black and from red.

Parallel Lives

Savannah

Endless Sands

{T}: Add {C}.
{2}, {T}: Exile target creature you control.
{4}, {T}, Sacrifice this land: Return each creature card exiled with this land to the battlefield under its owner's control.

Nyxbloom Ancient

Trample
If you tap a permanent for mana, it produces three times as much of that mana instead.

Zuran Orb

Druid of the Anima

Desert of the Fervent

This land enters tapped.
{T}: Add {R}.
Cycling {1}{R} ({1}{R}, Discard this card: Draw a card.)

Burst Lightning

Kicker {4} (You may pay an additional {4} as you cast this spell.)
Burst Lightning deals 2 damage to any target. If this spell was kicked, it deals 4 damage instead.

Temple Garden

({T}: Add {G} or {W}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Birds of Paradise

Creosote Heath

This land enters tapped.
When this land enters, it deals 1 damage to target opponent.
{T}: Add {G} or {W}.

Knight of New Alara

Each other multicolored creature you control gets +1/+1 for each of its colors.

Vesuva

You may have this land enter tapped as a copy of any land on the battlefield.

Dune Chanter

Reach
Lands you control and land cards you own that aren't on the battlefield are Deserts in addition to their other types.
Lands you control have "{T}: Add one mana of any color."
{T}: Mill two cards. You gain 1 life for each land card milled this way.

Echoing Deeps

You may have this land enter tapped as a copy of any land card in a graveyard, except it's a Cave in addition to its other types.
{T}: Add {C}.

Desert of the True

This land enters tapped.
{T}: Add {W}.
Cycling {1}{W} ({1}{W}, Discard this card: Draw a card.)

Twinflame Tyrant

Flying
If a source you control would deal damage to an opponent or a permanent an opponent controls, it deals double that damage instead.

Sol Ring

Cathars' Crusade

Whenever a creature you control enters, put a +1/+1 counter on each creature you control.

Bristling Backwoods

This land enters tapped.
When this land enters, it deals 1 damage to target opponent.
{T}: Add {R} or {G}.

Crop Rotation

As an additional cost to cast this spell, sacrifice a land.
Search your library for a land card, put that card onto the battlefield, then shuffle.

Arid Archway

This land enters tapped.
When this land enters, return a land you control to its owner's hand. If another Desert was returned this way, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{T}: Add {C}{C}.

Sacred Foundry

({T}: Add {R} or {W}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Rienne, Angel of Rebirth

Flying
Other multicolored creatures you control get +1/+0.
Whenever another multicolored creature you control dies, return it to its owner's hand at the beginning of the next end step.