Chainweb Aracnir — ruling 1

If Chainweb Aracnir leaves the battlefield before its triggered ability resolves, use its power as it last existed on the battlefield to determine how much damage it deals.

Chainweb Aracnir — ruling 2

Escape's permission doesn't change when you may cast the spell from your graveyard.

Chainweb Aracnir — ruling 3

To determine the total cost of a spell, start with the mana cost or alternative cost you're paying (such as an escape cost), add any cost increases, then apply any cost reductions. The mana value of the spell remains unchanged, no matter what the total cost to cast it was and no matter whether an alternative cost was paid.

Chainweb Aracnir — ruling 4

After an escaped spell resolves, it returns to its owner's graveyard if it's not a permanent spell. If it is a permanent spell, it enters the battlefield and will return to its owner's graveyard if it dies later. Perhaps it will escape again—good underworld security is so hard to come by these days.

Chainweb Aracnir — ruling 5

If a card has multiple abilities giving you permission to cast it, such as two escape abilities or an escape ability and a flashback ability, you choose which one to apply. The others have no effect.

Chainweb Aracnir — ruling 6

If you cast a spell with its escape permission, you can't choose to apply any other alternative costs or to cast it without paying its mana cost. If it has any additional costs, you must pay those.

Chainweb Aracnir — ruling 7

If a card with escape is put into your graveyard during your turn, you'll be able to cast it right away if it's legal to do so, before an opponent can take any actions.

Chainweb Aracnir — ruling 8

Once you begin casting a spell with escape, it immediately moves to the stack. Players can't take any other actions until you're done casting the spell.

Chainweb Aracnir : règles, fonctionnement et interactions (MTG)

Chainweb Aracnir 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

Reach When this creature enters, it deals damage equal to its power to target creature with flying an opponent controls. Escape—, Exile four other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.) This creature escapes with three +1/+1 counters on it.

How it works : Chainweb Aracnir

Original English text — Wizards of the Coast / Scryfall

#1January 24, 2020· Wizards of the Coast
If Chainweb Aracnir leaves the battlefield before its triggered ability resolves, use its power as it last existed on the battlefield to determine how much damage it deals.
No other card is named in this ruling.
#2January 24, 2020· Wizards of the Coast
Escape's permission doesn't change when you may cast the spell from your graveyard.
No other card is named in this ruling.
#3January 24, 2020· Wizards of the Coast
To determine the total cost of a spell, start with the mana cost or alternative cost you're paying (such as an escape cost), add any cost increases, then apply any cost reductions. The mana value of the spell remains unchanged, no matter what the total cost to cast it was and no matter whether an alternative cost was paid.
No other card is named in this ruling.
#4January 24, 2020· Wizards of the Coast
After an escaped spell resolves, it returns to its owner's graveyard if it's not a permanent spell. If it is a permanent spell, it enters the battlefield and will return to its owner's graveyard if it dies later. Perhaps it will escape again—good underworld security is so hard to come by these days.
No other card is named in this ruling.
#5January 24, 2020· Wizards of the Coast
If a card has multiple abilities giving you permission to cast it, such as two escape abilities or an escape ability and a flashback ability, you choose which one to apply. The others have no effect.
No other card is named in this ruling.
#6January 24, 2020· Wizards of the Coast
If you cast a spell with its escape permission, you can't choose to apply any other alternative costs or to cast it without paying its mana cost. If it has any additional costs, you must pay those.
No other card is named in this ruling.
#7January 24, 2020· Wizards of the Coast
If a card with escape is put into your graveyard during your turn, you'll be able to cast it right away if it's legal to do so, before an opponent can take any actions.
No other card is named in this ruling.
#8January 24, 2020· Wizards of the Coast
Once you begin casting a spell with escape, it immediately moves to the stack. Players can't take any other actions until you're done casting the spell.
No other card is named in this ruling.