Glademuse — ruling 1

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.

Glademuse — ruling 2

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

Glademuse : règles, fonctionnement et interactions (MTG)

Glademuse 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

Whenever a player casts a spell, if it's not their turn, that player draws a card.

How it works : Glademuse

Original English text — Wizards of the Coast / Scryfall

#1April 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.
#2April 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.