Explore the Underdark

Search your library for up to two basic land cards and/or Gate cards, put them onto the battlefield tapped, then shuffle.
You take the initiative.

Scaled Herbalist

{T}: You may put a land card from your hand onto the battlefield.

Circuitous Route

Search your library for up to two basic land cards and/or Gate cards, put them onto the battlefield tapped, then shuffle.

Izzet Guildgate

Izzet Guildgate enters tapped.
{T}: Add {U} or {R}.

Mina and Denn, Wildborn

You may play an additional land on each of your turns.
{R}{G}, Return a land you control to its owner's hand: Target creature gains trample until end of turn.

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.

Plaza of Harmony

When Plaza of Harmony enters, if you control two or more Gates, you gain 3 life.
{T}: Add {C}.
{T}: Add one mana of any type that a Gate you control could produce.

Spelunking

When Spelunking 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.

Citadel Gate

Citadel Gate enters tapped.
As Citadel Gate enters, choose a color other than white.
{T}: Add {W} or one mana of the chosen color.

Heap Gate

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{1}, {T}, Tap an untapped Gate you control: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Ruinous Ultimatum

Destroy all nonland permanents your opponents control.

Sylvan Scrying

Search your library for a land card, reveal it, put it into your hand, then shuffle.

Manor Gate

Manor Gate enters tapped.
As Manor Gate enters, choose a color other than green.
{T}: Add {G} or one mana of the chosen color.

Rampaging Baloths

Trample
Landfall — Whenever a land you control enters, you may create a 4/4 green Beast creature token.

Sakura-Tribe Scout

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

Guild Summit

When Guild Summit enters, you may tap any number of untapped Gates you control. Draw a card for each Gate tapped this way.
Whenever a Gate you control enters, draw a card.

Archway Angel

Flying
When Archway Angel enters, you gain 2 life for each Gate you control.

Reshape the Earth

Search your library for up to ten land cards, put them onto the battlefield tapped, then shuffle.

Avenger of Zendikar

When Avenger of Zendikar enters, create a 0/1 green Plant creature token for each land you control.
Landfall — Whenever a land you control enters, you may put a +1/+1 counter on each Plant creature you control.

Nylea's Intervention

Choose one —
• Search your library for up to X land cards, reveal them, put them into your hand, then shuffle.
• Nylea's Intervention deals twice X damage to each creature with flying.

Skyshroud Ranger

{T}: You may put a land card from your hand onto the battlefield. Activate only as a sorcery.

Plains

Thalia and The Gitrog Monster

First strike, deathtouch
You may play an additional land on each of your turns.
Creatures and nonbasic lands your opponents control enter tapped.
Whenever Thalia and The Gitrog Monster attacks, sacrifice a creature or land, then draw a card.

Orzhov Guildgate

Orzhov Guildgate enters tapped.
{T}: Add {W} or {B}.

Maze's End

Maze's End enters tapped.
{T}: Add {C}.
{3}, {T}, Return Maze's End to its owner's hand: Search your library for a Gate card, put it onto the battlefield, then shuffle. If you control ten or more Gates with different names, you win the game.

Cultivator Colossus

Trample
Cultivator Colossus's power and toughness are each equal to the number of lands you control.
When Cultivator Colossus enters, you may put a land card from your hand onto the battlefield tapped. If you do, draw a card and repeat this process.

Boros Guildgate

Boros Guildgate enters tapped.
{T}: Add {R} or {W}.

Tiller Engine

Whenever a land you control enters tapped, choose one —
• Untap that land.
• Tap target nonland permanent an opponent controls.

Crackling Perimeter

Tap an untapped Gate you control: Crackling Perimeter deals 1 damage to each opponent.

Rakdos Guildgate

Rakdos Guildgate enters tapped.
{T}: Add {B} or {R}.

Gateway Plaza

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

Swamp

The World Tree

The World Tree enters tapped.
{T}: Add {G}.
As long as you control six or more lands, lands you control have "{T}: Add one mana of any color."
{W}{W}{U}{U}{B}{B}{R}{R}{G}{G}, {T}, Sacrifice The World Tree: Search your library for any number of God cards, put them onto the battlefield, then shuffle.

Gatecreeper Vine

Defender
When Gatecreeper Vine enters, you may search your library for a basic land card or a Gate card, reveal it, put it into your hand, then shuffle.

Rude Awakening

Choose one —
• Untap all lands you control.
• Until end of turn, lands you control become 2/2 creatures that are still lands.
Entwine {2}{G} (Choose both if you pay the entwine cost.)

Eureka Moment

Draw two cards. You may put a land card from your hand onto the battlefield.

Walking Atlas

Kenrith, the Returned King

{R}: All creatures gain trample and haste until end of turn.
{1}{G}: Put a +1/+1 counter on target creature.
{2}{W}: Target player gains 5 life.
{3}{U}: Target player draws a card.
{4}{B}: Put target creature card from a graveyard onto the battlefield under its owner's control.

Tatyova, Benthic Druid

Landfall — Whenever a land you control enters, you gain 1 life and draw a card.

Baldur's Gate

{T}: Add {C}.
{2}, {T}: Add X mana of any one color, where X is the number of other Gates you control.

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.

Echoing Deeps

You may have Echoing Deeps 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}.

Hold the Gates

Creatures you control get +0/+1 for each Gate you control and have vigilance.

Rites of Flourishing

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 their turns.

Archelos, Lagoon Mystic

As long as Archelos, Lagoon Mystic is tapped, other permanents enter tapped.
As long as Archelos is untapped, other permanents enter untapped.

Basilisk Gate

{T}: Add {C}.
{2}, {T}: Target creature gets +X/+X until end of turn, where X is the number of Gates you control. Activate only as a sorcery.

Dryad of the Ilysian Grove

You may play an additional land on each of your turns.
Lands you control are every basic land type in addition to their other types.

Gates Ablaze

Gates Ablaze deals X damage to each creature, where X is the number of Gates you control.

Gruul Guildgate

Gruul Guildgate enters tapped.
{T}: Add {R} or {G}.

Azorius Guildgate

Azorius Guildgate enters tapped.
{T}: Add {W} or {U}.

The Mending of Dominaria

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Mill two cards, then you may return a creature card from your graveyard to your hand.
III — Return all land cards from your graveyard to the battlefield, then shuffle your graveyard into your library.

Black Dragon Gate

Black Dragon Gate enters tapped.
As Black Dragon Gate enters, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Azusa, Lost but Seeking

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

Golgari Guildgate

Golgari Guildgate enters tapped.
{T}: Add {B} or {G}.

Selesnya Guildgate

Selesnya Guildgate enters tapped.
{T}: Add {G} or {W}.

Oracle of Mul Daya

You may play an additional land on each of your turns.
Play with the top card of your library revealed.
You may play lands from the top of your library.

Thran Portal

Thran Portal enters tapped unless you control two or fewer other lands.
As Thran Portal enters, choose a basic land type.
Thran Portal is the chosen type in addition to its other types.
Mana abilities of Thran Portal cost an additional 1 life to activate.

Simic Guildgate

Simic Guildgate enters tapped.
{T}: Add {G} or {U}.

Urban Evolution

Draw three cards. You may play an additional land this turn.

Dimir Guildgate

Dimir Guildgate enters tapped.
{T}: Add {U} or {B}.

Wayward Swordtooth

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
You may play an additional land on each of your turns.
Wayward Swordtooth can't attack or block unless you have the city's blessing.

Forest

Cliffgate

Cliffgate enters tapped.
As Cliffgate enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Gatebreaker Ram

Gatebreaker Ram gets +1/+1 for each Gate you control.
As long as you control two or more Gates, Gatebreaker Ram has vigilance and trample.

Island

The Black Gate

As The Black Gate enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {B}.
{1}{B}, {T}: Choose a player with the most life or tied for most life. Target creature can't be blocked by creatures that player controls this turn.

Open the Way

X can't be greater than the number of players in the game.
Reveal cards from the top of your library until you reveal X land cards. Put those land cards onto the battlefield tapped and the rest on the bottom of your library in a random order.

Wilderness Reclamation

At the beginning of your end step, untap all lands you control.

Gretchen Titchwillow

{2}{G}{U}: Draw a card. You may put a land card from your hand onto the battlefield.

Titania's Command

Choose two —
• Exile target player's graveyard. You gain 1 life for each card exiled this way.
• Search your library for up to two land cards, put them onto the battlefield tapped, then shuffle.
• Create two 2/2 green Bear creature tokens.
• Put two +1/+1 counters on each creature you control.

Nine-Fingers Keene

Menace
Ward—Pay 9 life.
Whenever Nine-Fingers Keene deals combat damage to a player, look at the top nine cards of your library. You may put a Gate card from among them onto the battlefield. Then if you control nine or more Gates, put the rest into your hand. Otherwise, put the rest on the bottom of your library in a random order.

Biomancer's Familiar

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.
{T}: The next time target creature adapts this turn, it adapts as though it had no +1/+1 counters on it.

Llanowar Scout

Mountain

Sea Gate

Sea Gate enters tapped.
As Sea Gate enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Gond Gate

Gates you control enter untapped.
{T}: Add {C}.
{T}: Add one mana of any color that a Gate you control could produce.

Hour of Promise

Search your library for up to two land cards, put them onto the battlefield tapped, then shuffle. Then if you control three or more Deserts, create two 2/2 black Zombie creature tokens.

Animist's Awakening

Reveal the top X cards of your library. Put all land cards from among them onto the battlefield tapped and the rest on the bottom of your library in a random order.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, untap those lands.