tehuda no kaado wo sutehuda ni suru.

In card-game Japanese, 手札 means the cards in a player's hand.

A few useful points:

• It does not mean just a physical hand.
• It refers to the set of cards you are currently holding.
• In English, this is often just your hand.

So 手札 is a game term, not a body-part word in this sentence.

Here, の links two nouns.

• 手札 = hand
• カード = card(s)

So 手札のカード means something like:

• the card(s) in your hand
• a card from your hand

This is one of the most common uses of の. It often works like of, but in natural English it is usually better understood here as in or from.

Because 手札 and カード are not exactly the same thing.

• 手札 = your whole hand as a set
• カード = the individual card(s)

So 手札のカード focuses on the card or cards that belong to your hand.

If you said 手札を捨札にする, it would sound more like you are making your entire hand into discarded cards, in other words discarding the whole hand.

を marks the thing being directly acted on.

Here, that thing is カード.

So in:

手札のカードを捨札にする

the card(s) from your hand are what the action is being done to.

This fits the common pattern:

X を Y にする

= make/put X into Y

In this sentence, にする is part of the pattern:

XをYにする

This pattern means:

• make X into Y
• put X into the state/category Y
• treat X as Y

So カードを捨札にする means to make the card a discarded card, or more naturally in game English, to put it into the discard pile.

It does not mean some magical physical transformation. It is a very normal Japanese way to describe a result or status change.

Here, に marks the resulting state or destination.

The idea is that the card ends up as:

• part of the discard pile
• in discarded status

So:

• を marks the thing affected
• に marks what it becomes or where it ends up

That is why XをYにする works so often in Japanese.

Both are possible, but they feel a little different.

• 捨てる = to throw away / discard
• 捨札にする = to make into a discard, or put into the discard pile

In game language, 捨札にする is more specific and mechanical. It clearly tells you the result in game terms: the card goes to the discard area.

So 捨てる is more general, while 捨札にする sounds more like rulebook wording.

It can mean either, depending on context.

In card-game Japanese, 捨札 can refer to:

• a discarded card
• discarded cards in general
• the discard pile

In this sentence, the natural understanding is the discard pile or discard area: the card becomes part of the discarded cards.

Japanese often leaves out the subject when it is obvious.

So there is no stated you, but in a game rule or card effect, that is usually understood from context.

Also, the plain form する is often used in:

• rulebooks
• instructions
• card effect text
• system messages

So this can function like an instruction even though it is not using an English-style imperative form.

Depending on context, English might translate it as either:

• Discard a card from your hand.
• You discard a card from your hand.

Japanese nouns usually do not show singular vs plural by themselves.

So カード can mean:

• a card
• cards

The exact number depends on context.

If the game wants to be specific, Japanese often adds something like:

• 一枚 = one card
• 二枚 = two cards
• すべて = all
• 好きなだけ = as many as you like

So without that kind of wording, the number is not fully specified by カード alone.

Not necessarily.

Because Japanese does not automatically mark singular/plural, 手札のカード can be understood as one or more cards depending on the surrounding rules.

If the game specifically means one card, it will often say 手札のカード一枚.

If it means all cards in your hand, it might say something like 手札をすべて or 手札のカードすべて.

So context is very important.

No. In normal Japanese writing, this would usually be written without spaces:

手札のカードを捨札にする。

Spaces are often added in:

• beginner materials
• children’s materials
• game UI text
• learning apps

They are there to make the parts easier to read, not because standard Japanese requires them.

Both forms exist.

• 捨て札 is the fuller spelling with okurigana
• 捨札 is a compact compound-style spelling

In games, rulebooks, and card text, the shortened form 捨札 is very common because it looks neat and feels like a fixed game term.

So this is mostly a spelling/style issue, not a major grammar difference.