Surtland Elementalist — ruling 1

A Giant card is a creature card with the creature type Giant. Presumably, it will be the same size as all your other cards.

Surtland Elementalist — ruling 2

If you cast a spell using Surtland Elementalist’s triggered ability, you do so as part of the resolution of that ability. You can’t wait to cast the spell later in the turn. Timing permissions based on the card’s type are ignored, and the spell will resolve before blockers are declared.

Surtland Elementalist — ruling 3

If you cast a spell “without paying its mana cost,” you can’t choose to cast it for any alternative costs. You can, however, pay additional costs, such as kicker costs. If the card has any mandatory additional costs, those must be paid to cast the spell.

Surtland Elementalist — ruling 4

If the spell has {X} in its mana cost, you must choose 0 as the value of X.

Surtland Elementalist : règles, fonctionnement et interactions (MTG)

Surtland Elementalist is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

As an additional cost to cast this spell, reveal a Giant card from your hand or pay . Whenever this creature attacks, you may cast an instant or sorcery spell from your hand without paying its mana cost.

How it works : Surtland Elementalist

Original English text — Wizards of the Coast / Scryfall

#1February 5, 2021· Wizards of the Coast
A Giant card is a creature card with the creature type Giant. Presumably, it will be the same size as all your other cards.
No other card is named in this ruling.
#2February 5, 2021· Wizards of the Coast
If you cast a spell using Surtland Elementalist’s triggered ability, you do so as part of the resolution of that ability. You can’t wait to cast the spell later in the turn. Timing permissions based on the card’s type are ignored, and the spell will resolve before blockers are declared.
No other card is named in this ruling.
#3February 5, 2021· Wizards of the Coast
If you cast a spell “without paying its mana cost,” you can’t choose to cast it for any alternative costs. You can, however, pay additional costs, such as kicker costs. If the card has any mandatory additional costs, those must be paid to cast the spell.
No other card is named in this ruling.
#4February 5, 2021· Wizards of the Coast
If the spell has in its mana cost, you must choose 0 as the value of X.
No other card is named in this ruling.