Rosheen Meanderer — ruling 1

A “cost that contains {X}” may be a spell’s total cost, an activated ability’s cost, a suspend cost, or a cost you’re asked to pay as part of the resolution of a spell or ability (such as Condescend). A spell’s total cost includes either its mana cost (printed in the upper right corner) or its alternative cost (such as flashback), as well as any additional costs (such as kicker). If it’s something you can spend mana on, it’s a cost. If that cost includes the {X} symbol in it, you can spend mana generated by Rosheen on that cost.

Rosheen Meanderer — ruling 2

You can spend mana generated by Rosheen on any part of a cost that contains {X}. You’re not limited to spending it only on the {X} part.

Rosheen Meanderer — ruling 3

You can spend mana generated by Rosheen on a cost that includes {X} even if you’ve chosen an X of 0, or if the card specifies that you can spend only colored mana on X. (You’ll have to spend Rosheen’s mana on a different part of that cost, of course.)

Rosheen Meanderer — ruling 4

You don’t have to spend all four mana on the same cost.

Rosheen Meanderer : règles, fonctionnement et interactions (MTG)

Rosheen Meanderer 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

: Add . Spend this mana only on costs that contain .

How it works : Rosheen Meanderer

Original English text — Wizards of the Coast / Scryfall

#1November 17, 2017· Wizards of the Coast
A “cost that contains ” may be a spell’s total cost, an activated ability’s cost, a suspend cost, or a cost you’re asked to pay as part of the resolution of a spell or ability (such as Condescend). A spell’s total cost includes either its mana cost (printed in the upper right corner) or its alternative cost (such as flashback), as well as any additional costs (such as kicker). If it’s something you can spend mana on, it’s a cost. If that cost includes the symbol in it, you can spend mana generated by Rosheen on that cost.
No other card is named in this ruling.
#2November 17, 2017· Wizards of the Coast
You can spend mana generated by Rosheen on any part of a cost that contains . You’re not limited to spending it only on the part.
No other card is named in this ruling.
#3November 17, 2017· Wizards of the Coast
You can spend mana generated by Rosheen on a cost that includes even if you’ve chosen an X of 0, or if the card specifies that you can spend only colored mana on X. (You’ll have to spend Rosheen’s mana on a different part of that cost, of course.)
No other card is named in this ruling.
#4November 17, 2017· Wizards of the Coast
You don’t have to spend all four mana on the same cost.
No other card is named in this ruling.