Dissolve — ruling 1

When you scry, you may put all the cards you look at back on top of your library, you may put all of those cards on the bottom of your library, or you may put some of those cards on top and the rest of them on the bottom.

Dissolve — ruling 2

You choose how to order cards returned to your library after scrying no matter where you put them.

Dissolve — ruling 3

You perform the actions stated on a card in sequence. For some spells and abilities, that means you'll scry last. For others, that means you'll scry and then perform other actions.

Dissolve — ruling 4

Scry appears on some spells and abilities with one or more targets. If all of the spell or ability's targets are illegal when it tries to resolve, it won't resolve and none of its effects will happen. You won't scry.

Dissolve : règles, fonctionnement et interactions (MTG)

Dissolve 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

Counter target spell. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

How it works : Dissolve

Original English text — Wizards of the Coast / Scryfall

#1September 15, 2013· Wizards of the Coast
When you scry, you may put all the cards you look at back on top of your library, you may put all of those cards on the bottom of your library, or you may put some of those cards on top and the rest of them on the bottom.
No other card is named in this ruling.
#2September 15, 2013· Wizards of the Coast
You choose how to order cards returned to your library after scrying no matter where you put them.
No other card is named in this ruling.
#3September 15, 2013· Wizards of the Coast
You perform the actions stated on a card in sequence. For some spells and abilities, that means you'll scry last. For others, that means you'll scry and then perform other actions.
No other card is named in this ruling.
#4September 15, 2013· Wizards of the Coast
Scry appears on some spells and abilities with one or more targets. If all of the spell or ability's targets are illegal when it tries to resolve, it won't resolve and none of its effects will happen. You won't scry.
No other card is named in this ruling.

Interactions with other cards

These cards' text mentions Dissolve.

Gelatinous Cube

Engulf — When this creature enters, exile target non-Ooze creature an opponent controls until this creature leaves the battlefield. Dissolve — {X}{B}: Put target creature card with mana value X exiled with this creature into its owner's graveyard.