River's Grasp — ruling 1

This spell cares about what mana was spent to pay its total cost, not just what mana was spent to pay the hybrid mana symbol in its cost.

River's Grasp — ruling 2

This spell checks on resolution to see if any mana of the appropriate colors were spent to pay its cost. It doesn’t matter how much mana of that color was spent; the effect isn’t multiplied.

River's Grasp — ruling 3

If this spell is copied, the copy will not have had any colors of mana paid for it, no matter what colors were spent on the original spell.

River's Grasp : règles, fonctionnement et interactions (MTG)

River's Grasp 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

If was spent to cast this spell, return up to one target creature to its owner's hand. If was spent to cast this spell, target player reveals their hand, you choose a nonland card from it, then that player discards that card. (Do both if was spent.)

How it works : River's Grasp

Original English text — Wizards of the Coast / Scryfall

#1June 8, 2016· Wizards of the Coast
This spell cares about what mana was spent to pay its total cost, not just what mana was spent to pay the hybrid mana symbol in its cost.
No other card is named in this ruling.
#2June 8, 2016· Wizards of the Coast
This spell checks on resolution to see if any mana of the appropriate colors were spent to pay its cost. It doesn’t matter how much mana of that color was spent; the effect isn’t multiplied.
No other card is named in this ruling.
#3June 8, 2016· Wizards of the Coast
If this spell is copied, the copy will not have had any colors of mana paid for it, no matter what colors were spent on the original spell.
No other card is named in this ruling.