Chandra Ablaze — ruling 1

If you activate Chandra Ablaze's first ability, you don't discard a card until the ability resolves. You may activate the ability even if your hand is empty. You choose a target as you activate the ability even if you have no red cards in hand at that time.

Chandra Ablaze — ruling 2

As the first ability resolves, nothing happens if your hand is empty. But if you have any cards in hand, you must discard one. If you discard a nonred card, Chandra doesn't deal any damage.

Chandra Ablaze — ruling 3

If the creature targeted by the first ability is an illegal target by the time it resolves, the entire ability doesn't resolve. You won't discard a card.

Chandra Ablaze — ruling 4

You may activate Chandra's second ability even if your hand is empty. As it resolves, a player whose hand is empty simply draws three cards.

Chandra Ablaze — ruling 5

You cast red instant cards and red sorcery cards from your graveyard as part of the resolution of Chandra Ablaze's third ability. You don't choose which ones to cast until you're actually doing so as the ability resolves. You cast only the ones you want to, and you may cast them in any order. Timing restrictions based on the card's type (if it's a sorcery) are ignored. Other restrictions are not (such as "Cast [this card] only during combat"). Each card you cast this way is put on the stack, then the ability finishes resolving. Those spells will then resolve as normal, one at a time, in the opposite order that they were put on the stack. They'll go back to the graveyard as they resolve.

Chandra Ablaze — ruling 6

If you cast a card "without paying its mana cost," you can't pay any alternative costs. You can pay additional costs, such as kicker costs.

Chandra Ablaze : règles, fonctionnement et interactions (MTG)

Chandra Ablaze 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

+1: Discard a card. If a red card is discarded this way, Chandra deals 4 damage to any target. −2: Each player discards their hand, then draws three cards. −7: Cast any number of red instant and/or sorcery cards from your graveyard without paying their mana costs.

How it works : Chandra Ablaze

Original English text — Wizards of the Coast / Scryfall

#1October 1, 2009· Wizards of the Coast
If you activate Chandra Ablaze's first ability, you don't discard a card until the ability resolves. You may activate the ability even if your hand is empty. You choose a target as you activate the ability even if you have no red cards in hand at that time.
No other card is named in this ruling.
#2October 1, 2009· Wizards of the Coast
As the first ability resolves, nothing happens if your hand is empty. But if you have any cards in hand, you must discard one. If you discard a nonred card, Chandra doesn't deal any damage.
No other card is named in this ruling.
#3October 1, 2009· Wizards of the Coast
If the creature targeted by the first ability is an illegal target by the time it resolves, the entire ability doesn't resolve. You won't discard a card.
No other card is named in this ruling.
#4October 1, 2009· Wizards of the Coast
You may activate Chandra's second ability even if your hand is empty. As it resolves, a player whose hand is empty simply draws three cards.
No other card is named in this ruling.
#5October 1, 2009· Wizards of the Coast
You cast red instant cards and red sorcery cards from your graveyard as part of the resolution of Chandra Ablaze's third ability. You don't choose which ones to cast until you're actually doing so as the ability resolves. You cast only the ones you want to, and you may cast them in any order. Timing restrictions based on the card's type (if it's a sorcery) are ignored. Other restrictions are not (such as "Cast [this card] only during combat"). Each card you cast this way is put on the stack, then the ability finishes resolving. Those spells will then resolve as normal, one at a time, in the opposite order that they were put on the stack. They'll go back to the graveyard as they resolve.
No other card is named in this ruling.
#6October 1, 2009· Wizards of the Coast
If you cast a card "without paying its mana cost," you can't pay any alternative costs. You can pay additional costs, such as kicker costs.
No other card is named in this ruling.