Catch // Release — ruling 1

Catch can target any permanent, including one that’s untapped or one you already control.

Catch // Release — ruling 2

If a player names a card, the player may name either half of a split card, but not both. A split card has the chosen name if one of its two names matches the chosen name.

Catch // Release — ruling 3

If you cast Catch/Release as a fused split spell, you can sacrifice the permanent you just gained control of.

Catch // Release — ruling 4

If you’re casting a split card with fuse from any zone other than your hand, you can’t cast both halves. You’ll only be able to cast one half or the other.

Catch // Release — ruling 5

To cast a fused split spell, pay both of its mana costs. While the spell is on the stack, its mana value is the total amount of mana in both costs.

Catch // Release — ruling 6

You can choose the same object as the target of each half of a fused split spell, if appropriate.

Catch // Release — ruling 7

When resolving a fused split spell with multiple targets, treat it as you would any spell with multiple targets. If all targets are illegal when the spell tries to resolve, the spell doesn’t resolve and none of its effects happen. If at least one target is still legal at that time, the spell resolves, but an illegal target can’t perform any actions or have any actions performed on it.

Catch // Release — ruling 8

When a fused split spell resolves, follow the instructions of the left half first, then the instructions on the right half.

Catch // Release : règles, fonctionnement et interactions (MTG)

Catch // Release 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

Gain control of target permanent until end of turn. Untap it. It gains haste until end of turn. Fuse (You may cast one or both halves of this card from your hand.) Each player sacrifices an artifact, a creature, an enchantment, a land, and a planeswalker of their choice. Fuse (You may cast one or both halves of this card from your hand.)

How it works : Catch // Release

Original English text — Wizards of the Coast / Scryfall

#1April 15, 2013· Wizards of the Coast
Catch can target any permanent, including one that’s untapped or one you already control.
No other card is named in this ruling.
#2April 15, 2013· Wizards of the Coast
If a player names a card, the player may name either half of a split card, but not both. A split card has the chosen name if one of its two names matches the chosen name.
No other card is named in this ruling.
#3April 15, 2013· Wizards of the Coast
If you cast Catch/Release as a fused split spell, you can sacrifice the permanent you just gained control of.
No other card is named in this ruling.
#4April 15, 2013· Wizards of the Coast
If you’re casting a split card with fuse from any zone other than your hand, you can’t cast both halves. You’ll only be able to cast one half or the other.
No other card is named in this ruling.
#5April 15, 2013· Wizards of the Coast
To cast a fused split spell, pay both of its mana costs. While the spell is on the stack, its mana value is the total amount of mana in both costs.
No other card is named in this ruling.
#6April 15, 2013· Wizards of the Coast
You can choose the same object as the target of each half of a fused split spell, if appropriate.
No other card is named in this ruling.
#7April 15, 2013· Wizards of the Coast
When resolving a fused split spell with multiple targets, treat it as you would any spell with multiple targets. If all targets are illegal when the spell tries to resolve, the spell doesn’t resolve and none of its effects happen. If at least one target is still legal at that time, the spell resolves, but an illegal target can’t perform any actions or have any actions performed on it.
No other card is named in this ruling.
#8April 15, 2013· Wizards of the Coast
When a fused split spell resolves, follow the instructions of the left half first, then the instructions on the right half.
No other card is named in this ruling.
#9April 15, 2013· Wizards of the Coast
On the stack, a split spell that hasn’t been fused has only that half’s characteristics and mana value. The other half is treated as though it didn’t exist.
No other card is named in this ruling.
#10April 15, 2013· Wizards of the Coast
Some split cards with fuse have two monocolor halves of different colors. If such a card is cast as a fused split spell, the resulting spell is multicolored. If only one half is cast, the spell is the color of that half. While not on the stack, such a card is multicolored.
No other card is named in this ruling.
#11April 15, 2013· Wizards of the Coast
Some split cards with fuse have two halves that are both multicolored. That card is multicolored no matter which half is cast, or if both halves are cast. It’s also multicolored while not on the stack.
No other card is named in this ruling.
#12April 15, 2013· Wizards of the Coast
If you cast a split card with fuse from your hand without paying its mana cost, you can choose to use its fuse ability and cast both halves without paying their mana costs.
No other card is named in this ruling.
#13April 15, 2013· Wizards of the Coast
To resolve Release, the active player chooses a permanent they control for each of the listed types, then each other player in turn order does the same, then all the chosen permanents are sacrificed simultaneously.
No other card is named in this ruling.
#14April 15, 2013· Wizards of the Coast
If you control an artifact creature, a nonartifact creature, and no other artifacts or creatures, you must sacrifice both permanents. You must choose the artifact creature as the artifact and the nonartifact creature as the creature. The same is true for any combination of types—you sacrifice a number of permanents as close to five as possible.
No other card is named in this ruling.