Upgradable

"Upgradable" is an unofficial term used to refer to cards that transform themselves into a more powerful version under the conditions listed.

While no official keyword is used to denote the ability, precisely the same text is included on all of the Spellstone cards from the Kobolds & Catacombs expansion and Galakrond cards from Descent of Dragons with the text "([Do something] to upgrade)", as well as the Scheme cards from the Rise of Shadows expansion with the text "(Upgrades each turn!)".

Upgradable cards from Kobolds & Catacombs and Descent of Dragons will transform into stronger versions of itself when the conditions in the text is met, up to twice. Upgradable cards from Rise of Shadows have its value increment at the end of each turn while in your hand.

Spellstones

 * Any progress towards upgrades will be carried over into the card. For example, when you play an elemental with a fresh Lesser Ruby Spellstone, you will need to play one more elemental to upgrade it, and the card text will reflect it.
 * The cards will upgrade whenever an instance triggers an upgrade. For example, a Lesser Amethyst Spellstone will upgrade each time Spreading Madness hits your hero.
 * The cards cannot skip an upgrade level. For example, you cannot upgrade a Lesser Jasper Spellstone into a Greater Jasper Spellstone by gaining 6 Armor at once.
 * Cost-reduction effects that have been applied to the card (Ex. Primordial Glyph, Emperor Thaurissan) will not carry over when upgraded.
 * If the card meets its upgrade requirement as it is added to your hand, it will be upgraded. (i.e. Ultimate Infestation will upgrade Lesser Jasper Spellstone as it is drawn, and Chittering Tunneler will upgrade Lesser Amethyst Spellstone when it is discovered.)

Schemes

 * Schemes that are cast by minions will always be the lowest possible value. Additionally, Drustvar Horror will not upgrade Hagatha's Scheme while it's kept in your hand.

Galakrond

 * Galakrond work mostly identical to Spellstones, but do not have to be in your hand to be upgraded.

Fully upgraded
These cards are the Tier 3 fully upgraded cards.