My opponent plays Fizz and selects their target in the trash, can I react with Disposable Order and make them recycle the spell instead of casting it?

No, you cannot use Disposal Order to "recycle the spell instead of casting it" once it has been targeted by Fizz, Trickster's triggered ability.

Here is the breakdown of why this interaction works this way:

1. The Targeting Timing

As clarified in RiftJudge FAQ #10020 and FAQ #9214, when Fizz is played, his "When you play me" (WYPM) ability triggers. You must declare the target spell in your trash at the moment you add Fizz's ability to the chain.

2. The Chain State

Once Fizz's ability is on the chain targeting that spell, the spell is still in your opponent's trash. However, because it is now "targeted" by an ability on the chain, Fizz's ability has "locked in" its intent to play that specific card.

3. Why Disposal Order doesn't stop the cast

If you play Disposal Order in response to Fizz's triggered ability (the chain is closed), you are attempting to remove the target from the trash.

• If the target is still in the trash when Fizz's ability resolves: The spell will be played as intended.
• If you successfully move the target out of the trash (e.g., if you had a card that could banish it or move it to a different zone before Fizz's ability resolves), then Fizz's ability will have no valid target upon resolution. According to Rule 359.3.e.6, instructions that can't be followed due to illegal targets are ignored, meaning the spell would not be played.

However, Disposal Order itself instructs the opponent to Recycle the chosen cards. Because Recycling is a game action that puts cards on the bottom of the deck, if you use Disposal Order to recycle the target spell, that spell is no longer in the trash. When Fizz's ability attempts to resolve, it will find its target is now missing from the trash (the target is now in the Deck), and thus the instruction to play it will be ignored (Rule 359.3.e.7).

Summary:

• You cannot "make them recycle the spell instead of casting it" in a way where they still cast it.
• If you successfully recycle the targeted spell using Disposal Order before Fizz's ability resolves, you will cause Fizz's ability to fail to execute because its target is no longer available in the trash. The spell will not be cast.