Slitherwisp — ruling 1

If an effect allows you to cast a spell “as though” it has flash, Slitherwisp’s last ability won’t trigger.

Slitherwisp — ruling 2

An ability that triggers when a player casts a spell resolves before the spell that caused it to trigger. It resolves even if that spell is countered.

Slitherwisp — ruling 3

Players can cast spells and activate abilities after the triggered ability resolves but before the spell that caused it to trigger does.

Slitherwisp — ruling 4

In a Two-Headed Giant game, Slitherwisp’s last ability causes the opposing team to lose 2 life and you to draw one card.

Slitherwisp : règles, fonctionnement et interactions (MTG)

Slitherwisp 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

Flash Whenever you cast another spell that has flash, you draw a card and each opponent loses 1 life.

How it works : Slitherwisp

Original English text — Wizards of the Coast / Scryfall

#1April 17, 2020· Wizards of the Coast
If an effect allows you to cast a spell “as though” it has flash, Slitherwisp’s last ability won’t trigger.
No other card is named in this ruling.
#2April 17, 2020· Wizards of the Coast
An ability that triggers when a player casts a spell resolves before the spell that caused it to trigger. It resolves even if that spell is countered.
No other card is named in this ruling.
#3April 17, 2020· Wizards of the Coast
Players can cast spells and activate abilities after the triggered ability resolves but before the spell that caused it to trigger does.
No other card is named in this ruling.
#4April 17, 2020· Wizards of the Coast
In a Two-Headed Giant game, Slitherwisp’s last ability causes the opposing team to lose 2 life and you to draw one card.
No other card is named in this ruling.