Guerrilla Tactics

Guerrilla Tactics deals 2 damage to any target.
When a spell or ability an opponent controls causes you to discard Guerrilla Tactics, Guerrilla Tactics deals 4 damage to any target.

Flashfires

Volcanic Hammer

Volcanic Hammer deals 3 damage to any target.

City of Brass

Whenever City of Brass becomes tapped, it deals 1 damage to you.
{T}: Add one mana of any color.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Iron Maiden

At the beginning of each opponent's upkeep, Iron Maiden deals X damage to that player, where X is the number of cards in their hand minus 4.

Manabarbs

Whenever a player taps a land for mana, Manabarbs deals 1 damage to that player.

Chain Lightning

Chain Lightning deals 3 damage to any target. Then that player or that permanent's controller may pay {R}{R}. If the player does, they may copy this spell and may choose a new target for that copy.

Fire Ambush

Fire Ambush deals 3 damage to any target.

Shock

Lava Axe

Lava Axe deals 5 damage to target player or planeswalker.

Disenchant

Wheel of Fortune

Each player discards their hand, then draws seven cards.

Viashino Sandstalker

Haste (This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, return Viashino Sandstalker to its owner's hand. (Return it only if it's on the battlefield.)

Boil

Thunderbolt

Choose one —
• Thunderbolt deals 3 damage to target player or planeswalker.
• Thunderbolt deals 4 damage to target creature with flying.

Seal of Fire

Sacrifice Seal of Fire: It deals 2 damage to any target.

Lightning Blast

Lightning Blast deals 4 damage to any target.

Incinerate

Incinerate deals 3 damage to any target. A creature dealt damage this way can't be regenerated this turn.

Smoke

Players can't untap more than one creature during their untap steps.

Earthquake

Earthquake deals X damage to each creature without flying and each player.

Fireblast

You may sacrifice two Mountains rather than pay this spell's mana cost.
Fireblast deals 4 damage to any target.

Mishra's Factory

{T}: Add {C}.
{1}: Mishra's Factory becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.
{T}: Target Assembly-Worker creature gets +1/+1 until end of turn.

Plains

Viashino Sandscout

Haste (This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, return Viashino Sandscout to its owner's hand. (Return it only if it's on the battlefield.)

Pyrotechnics

Pyrotechnics deals 4 damage divided as you choose among any number of targets.

The Rack

As The Rack enters, choose an opponent.
At the beginning of the chosen player's upkeep, The Rack deals X damage to that player, where X is 3 minus the number of cards in their hand.

Mountain

Ghitu Slinger

Echo {2}{R} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Ghitu Slinger enters, it deals 2 damage to any target.

Goblin War Buggy

Haste
Echo {1}{R} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)