Blast from the Past

• WOTC Official Reminder Textofficial rules
  Madness — Madness [cost] (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)
• WOTC Official Reminder Textofficial rules
  Buyback — You may pay an additional cost as you cast this spell. If you do, put this card into your hand as it resolves.
• WOTC Official Reminder Textofficial rules
  Flashback — Flashback [cost] (You may cast this card from your graveyard for its flashback cost. Then exile it.)
• WOTC Official Reminder Textofficial rules
  Cycling — Cycling [cost] (Pay [cost], discard this card: Draw a card.)
• WOTC Official Reminder Textofficial rules
  Kicker — Kicker [cost] (You may pay an additional [cost] as you cast this spell.)

• WWizards of the Coast2020-02-29
  Official Ruling
  If you cycle Blast from the Past, you can then use madness to cast it. If you cast Blast from the Past using madness, you may also pay for kicker or buyback.
• WWizards of the Coast2020-02-29
  Official Ruling
  Flashback and buyback don't mix. If you cast Blast from the Past using flashback, it will be exiled rather than go back to your hand.
• WWizards of the Coast2020-02-29
  Official Ruling
  Flashback and kicker do mix. You can pay the kicker cost in addition to the flashback cost to get the extra Goblin token.
• WWizards of the Coast2022-12-08
  Official Ruling
  Casting a spell with madness ignores the timing rules based on the card's card type. For example, you can cast a sorcery with madness if you discard it during an opponent's turn.
• WWizards of the Coast2022-12-08
  Official Ruling
  A spell cast for its madness cost is put onto the stack like any other spell. It can be countered, copied, and so on. As it resolves, it's put onto the battlefield if it's a permanent card or into its owner's graveyard if it's an instant or sorcery card.
• WWizards of the Coast2022-12-08
  Official Ruling
  Cards are discarded in a Magic game only from a player's hand. Effects that put cards into a player's graveyard from anywhere else do not cause those cards to be discarded.
• WWizards of the Coast2022-12-08
  Official Ruling
  If you discard a card with madness to pay the cost of a spell or activated ability, that card's madness triggered ability (and the spell that card becomes, if you choose to cast it) will resolve before the spell or ability the discard paid for.
• WWizards of the Coast2022-12-08
  Official Ruling
  Madness works independently of why you're discarding the card. You could discard it to pay a cost, because a spell or ability tells you to, or because you have too many cards in your hand during your cleanup step. You can't discard a card with madness just because you want to, though.
• WWizards of the Coast2022-12-08
  Official Ruling
  To determine the total cost of a spell, start with the mana cost or alternative cost (such as a madness cost) you're paying, add any cost increases, then apply any cost reductions. The mana value of the spell is determined by only its mana cost, no matter what the total cost to cast that spell was.
• WWizards of the Coast2022-12-08
  Official Ruling
  A card with madness that's discarded counts as having been discarded even though it's put into exile rather than a graveyard. If it was discarded to pay a cost, that cost is still paid. Abilities that trigger when a card is discarded will still trigger.
• WWizards of the Coast2022-12-08
  Official Ruling
  If you discard a card with madness while a spell or ability is resolving, it moves immediately to exile. Continue resolving that spell or ability, noting that the card you discarded is not in your graveyard at this time. Its madness triggered ability will be placed onto the stack once that spell or ability has completely resolved.
• WWizards of the Coast2022-12-08
  Official Ruling
  If you choose not to cast a card with madness when the madness triggered ability resolves, it's put into your graveyard. Madness doesn't give you another chance to cast it later.
• WWizards of the Coast2024-11-08
  Official Ruling
  To determine a spell's total cost, start with the mana cost (or an alternative cost if another card's effect allows you to pay one instead), add any cost increases (such as kicker), then apply any cost reductions. The spell's mana value remains unchanged, no matter what the total cost to cast it was.
• WWizards of the Coast2024-11-08
  Official Ruling
  If a spell's kicker cost was paid, the spell is "kicked."
• WWizards of the Coast2024-11-08
  Official Ruling
  If a card or token enters as a copy of a permanent, the new permanent isn't kicked, even if the original was.
• WWizards of the Coast2024-11-08
  Official Ruling
  If you put a permanent with a kicker ability onto the battlefield without casting it, you can't kick it.
• WWizards of the Coast2024-11-08
  Official Ruling
  The kicker ability doesn't let you pay a kicker cost more than once.
• WWizards of the Coast2024-11-08
  Official Ruling
  If you copy a kicked spell on the stack, the copy is also kicked. If the copied spell is a permanent spell, the token the copy of that spell becomes when it enters is also kicked.

Rulings via Scryfall