Thundertrap Trainer — ruling 1

You can pay an offspring cost only once as you cast a spell with offspring. You can’t try to pay it multiple times to get more token copies.

Thundertrap Trainer — ruling 2

If the spell is countered, the offspring ability will not trigger, and no token will be created.

Thundertrap Trainer — ruling 3

If the spell resolves but the creature with offspring leaves the battlefield before the offspring ability resolves, you’ll still create a token copy of it.

Thundertrap Trainer — ruling 4

The token copies exactly what was printed on the original creature and nothing else, except it’s a 1/1 (unless that creature is copying something else; see below). It doesn’t copy whether that creature is tapped or untapped, whether it has any counters on it or Auras and Equipment attached to it, or any non-copy effects that have changed its types, color, or so on.

Thundertrap Trainer — ruling 5

In the rare case where the original creature is copying something else when the offspring ability resolves, the token enters as whatever that creature copied, except it’s a 1/1.

Thundertrap Trainer — ruling 6

Many creatures with offspring abilities have other abilities that refer to them as “this creature” rather than referring to them by name. This difference is for clarity purposes and does not change the function of any of these abilities.

Thundertrap Trainer — ruling 7

Any “enters” abilities of the copied creature will trigger when the token enters. Any “as [this creature] enters” or “[this creature] enters with” abilities of the copied creature will also work.

Thundertrap Trainer — ruling 8

The token created by the offspring ability isn’t “cast”, so abilities that trigger when a creature spell is cast won’t trigger for the copy.

Thundertrap Trainer : règles, fonctionnement et interactions (MTG)

Thundertrap Trainer 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

Offspring (You may pay an additional as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.) When this creature enters, look at the top four cards of your library. You may reveal a noncreature, nonland card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

How it works : Thundertrap Trainer

Original English text — Wizards of the Coast / Scryfall

#1July 26, 2024· Wizards of the Coast
You can pay an offspring cost only once as you cast a spell with offspring. You can’t try to pay it multiple times to get more token copies.
No other card is named in this ruling.
#2July 26, 2024· Wizards of the Coast
If the spell is countered, the offspring ability will not trigger, and no token will be created.
No other card is named in this ruling.
#3July 26, 2024· Wizards of the Coast
If the spell resolves but the creature with offspring leaves the battlefield before the offspring ability resolves, you’ll still create a token copy of it.
No other card is named in this ruling.
#4July 26, 2024· Wizards of the Coast
The token copies exactly what was printed on the original creature and nothing else, except it’s a 1/1 (unless that creature is copying something else; see below). It doesn’t copy whether that creature is tapped or untapped, whether it has any counters on it or Auras and Equipment attached to it, or any non-copy effects that have changed its types, color, or so on.
No other card is named in this ruling.
#5July 26, 2024· Wizards of the Coast
In the rare case where the original creature is copying something else when the offspring ability resolves, the token enters as whatever that creature copied, except it’s a 1/1.
No other card is named in this ruling.
#6July 26, 2024· Wizards of the Coast
Many creatures with offspring abilities have other abilities that refer to them as “this creature” rather than referring to them by name. This difference is for clarity purposes and does not change the function of any of these abilities.
No other card is named in this ruling.
#7July 26, 2024· Wizards of the Coast
Any “enters” abilities of the copied creature will trigger when the token enters. Any “as [this creature] enters” or “[this creature] enters with” abilities of the copied creature will also work.
No other card is named in this ruling.
#8July 26, 2024· Wizards of the Coast
The token created by the offspring ability isn’t “cast”, so abilities that trigger when a creature spell is cast won’t trigger for the copy.
No other card is named in this ruling.
#9July 26, 2024· Wizards of the Coast
In the rare case where the creature doesn’t have the offspring ability when it enters, the ability won’t trigger even if you paid the offspring cost.
No other card is named in this ruling.