Strictly better

Strictly better describes a card which is, in isolation from other effects, superior to another card in at least one respect, while being worse in zero respects. Cards are commonly found to be strictly better than others by virtue of lower cost, larger effect, instant speed, greater power or toughness, or more versatile or added effects.

Description
"Strictly better" status is not dependent on creature type. More generally, such comparisons between cards are made independent of any particular board state. Therefore, because of the sheer number of possible gameplay circumstances, for any given "strictly better" card, there is typically some imaginable set of circumstances in which it is, in fact, inferior to another card that would otherwise rank below it. This fact implies that a "strictly better" card might be more accurately termed "typically better", and that distinction sometimes confuses newer players. However, "strictly better" is well understood among experienced Magic players, and is the prevailing description of such a relationship between cards.

For example, Lightning Bolt is strictly better than Shock. Both are instants, both cost, and both can target either a creature or a player, but Lightning Bolt deals 3 damage, whereas Shock deals only 2 damage. Although Shock would be preferable to Lightning Bolt if, for example, your opponent controls a Mogg Maniac that you need to kill while you have 3 life, this doesn't preclude Lightning Bolt from being "strictly better," as said circumstances are incredibly niche.

Many pairs of cards are not directly comparable, and thus cannot be termed strictly better or worse. For example, Reprisal and Vanquish the Foul have similar effects, but the latter half of each effect cannot be compared to the other card. Despite Reprisal's lower cost and faster speed, it cannot be termed strictly better than Vanquish the Foul. However, Reprisal is strictly better than Smite the Monstrous</c>, because it has a lower cost and prevents regeneration while being worse in no respect.

The printing of a new strictly better card may make comparable cards obsolete, and this process left unchecked leads to power creep. As rarity has no factor on the definition of strictly better, this occurs relatively commonly with directly comparable cards printed in the same set. Less often, two commons such as Glory Seeker</c> and Knight of Cliffhaven</c> in Rise of the Eldrazi will have this relationship. This phenomenon of strictly better cards within the same set actually goes all the way back to Alpha (e.g., Gray Ogre</c> and Sedge Troll</c>).

=Examples=

More powerful at same cost
The following cards have the same cost, but one has an added ability or greater size.
 * Alloy Myr</c> is strictly better than Opaline Unicorn</c> because it has greater power.
 * Armored Griffin</c> is strictly better than Abbey Griffin</c> because it has greater toughness.
 * Ashcoat Bear</c> is strictly better than Grizzly Bears</c> (and its functional reprints) because it also has flash.
 * Deviant Glee</c> is strictly better than Unholy Strength</c> as it also can grant trample as an activated ability.
 * Elite Vanguard</c> is strictly better than Eager Cadet</c> because it has a greater power.
 * Ethereal Armor</c> is strictly better than <c>Lance</c> because it also grants a minimum of +1/+1.
 * <c>Giant Crab</c> is strictly better than <c>Homarid Warrior</c> as it doesn't tap to use its ability.
 * <c>Hovermyr</c> is strictly better than <c>Omega Myr</c> because it has the added ability of flying and vigilance.
 * <c>Makindi Griffin</c> is strictly better than <c>Spotted Griffin</c> because it has greater toughness.
 * <c>Sejiri Refuge</c> is strictly better than <c>Coastal Tower</c> because it gains life.
 * <c>Sporecap Spider</c> is strictly better than <c>Rib Cage Spider</c> because it has greater toughness.
 * <c>Wall of Vines</c> is strictly better than <c>Wall of Wood</c> because it also has reach.
 * <c>Yavimaya Wurm</c> is strictly better than <c>Craw Wurm</c> because it has trample.
 * <c>Lagonna-Band Trailblazer</c> is strictly better than <c>Yoked Ox</c> because it has an added "Heroic" ability.
 * <c>Dead Weight</c> is strictly better than <c>Weakness</c> because of the additional -1 toughness in the former over the latter.

More flexibility at same cost
The following cards have the same effect, but one is more restricted in its use.
 * <c>Coordinated Assault</c> is strictly better than <c>Kindled Fury</c>, because it can target an additional creature.
 * <c>Fury Charm</c> is strictly better than <c>Shatter</c>, because it has two other selectable modes.
 * <c>Jungle Shrine</c> is strictly better than <c>Shivan Oasis</c>, because it can provide an additional color of mana.
 * <c>Negate</c> is strictly better than <c>Flash Counter</c>, because it can counter additional types of spells.

Same effect but cost less
The following cards have the same effect, but one has a greater cost.
 * <c>Control Magic</c> is strictly better than <c>Mind Control</c>.
 * <c>Dead Weight</c> is strictly better than <c>Enfeeblement</c> and <c>Debilitating Injury</c>.
 * <c>Elvish Archers</c> is strictly better than <c>Hornet Cobra</c>.
 * <c>Goblin Tunneler</c> is strictly better than <c>Dwarven Nomad</c>.
 * <c>Lightning Bolt</c> is strictly better than <c>Shard Volley</c>.

Instant instead of sorcery
The following are cards that have the same effect and cost but are instants instead of sorceries.
 * <c>Boil</c> is strictly better than <c>Boiling Seas</c>.
 * <c>Howl from Beyond</c> is strictly better than <c>Bloodcurdling Scream</c>.
 * <c>Inner Struggle</c> is strictly better than <c>Wrack with Madness</c>.

Multiple upgrades
Some cards may be strictly better in multiple respects but are only strictly better overall if they have no attributes inferior to the card they are compared with.
 * <c>Back to Nature</c> is strictly better than <c>Tranquility</c> because the former costs less and is an instant instead of a sorcery.
 * <c>Vulshok Battlegear</c> is strictly better than <c>Warlord's Axe</c> because the former costs less to equip and gives a larger toughness bonus.
 * <c>Nova Cleric</c> is strictly better than <c>Squire</c> because the former costs less and has an additional ability.
 * <c>Flametongue Kavu</c> is strictly better than <c>Goblin Commando</c> because the latter has less power, costs more, and does less damage when it enters the battlefield.
 * <c>Whitesun's Passage</c> is strictly better than <c>Sacred Nectar</c> because the former gains more life and is an instant instead of a sorcery.
 * <c>Reprisal</c> is strictly better than <c>Smite the Monstrous</c> because the former prevents regeneration and has a lower mana cost.
 * <c>Dragon Mantle</c> is strictly better than <c>Firebreathing</c> because it also draws you a card.
 * <c>Strength of the Tajuru</c> is strictly better than <c>Stand Together</c> as they are identical when <c>Strength of the Tajuru</c> is kicked once and X=2, but Strength can also be cast for other configurations.

=References=