Tocca a un avversario scartare una carta.

In this sentence, tocca a means it is up to or it is [someone’s] turn to.

So:

• Tocca a un avversario = It’s an opponent’s turn / It’s up to an opponent

This is a very common Italian structure:

• Tocca a me = It’s my turn
• Tocca a te = It’s your turn
• Tocca a lui/lei = It’s his/her turn

With an infinitive after it, it means whose turn it is to do something:

• Tocca a me parlare = It’s my turn to speak
• Tocca a un avversario scartare una carta = It’s an opponent’s turn to discard a card

Because toccare in this meaning uses a before the person who has the turn.

So the pattern is:

• tocca a + person + infinitive

Examples:

• Tocca a Marco giocare = It’s Marco’s turn to play
• Tocca a noi scegliere = It’s our turn to choose

That a is required by the expression. You cannot say Tocca un avversario scartare una carta with this meaning.

Because after tocca a + someone, Italian normally uses an infinitive to say what that person has to do.

Structure:

• Tocca a + person + infinitive

So:

• Tocca a un avversario scartare una carta
• literally: It falls to an opponent to discard a card

Other examples:

• Tocca a me cucinare = It’s my turn to cook
• Tocca a te decidere = It’s up to you to decide

The infinitive works much like English to discard, to decide, to cook.

Because avversario begins with a vowel, so the masculine singular indefinite article is un.

Compare:

• un avversario
• un amico
• un uomo

You use uno before certain consonant sounds such as s + consonant, z, ps, gn, etc.:

• uno studente
• uno zaino
• uno psicologo

So avversario takes un, not uno.

Because carta is a feminine singular noun.

So the indefinite article is:

• masculine singular: un / uno
• feminine singular: una

Examples:

• un libro = a book
• uno studente = a student
• una carta = a card

If you were talking about more than one card, you could say:

• delle carte = some cards

Usually yes, especially in games, sports, or competitive situations.

Here, un avversario most naturally means an opponent in a game.

Depending on context, avversario can also mean:

• an adversary
• a rival
• an opposing player

In a card-game instruction, opponent is the most natural English equivalent.

It could, but it would mean something slightly different in tone.

• Tocca a un avversario scartare una carta = It’s an opponent’s turn to discard a card
• Un avversario deve scartare una carta = An opponent must discard a card

Tocca a focuses on whose turn/responsibility it is.
Deve focuses more directly on obligation.

In game instructions, tocca a is often used when the rule is about turn order or who is the affected player.

You might understand it, but it sounds less natural.

A more natural alternative would be:

• È il turno di un avversario: deve scartare una carta
• or simply
• Tocca a un avversario scartare una carta

In Italian, tocca a + person + infinitive is a very idiomatic and compact way to say this. It is especially common in spoken language and in instructions.

The structure is:

• Tocca a un avversario = It is up to an opponent
• scartare una carta = to discard a card

So the full pattern is:

• [tocca a + person] + [infinitive phrase]

Italian often keeps this order when using tocca a. It may feel slightly unusual to an English speaker because English often starts with the person:

• An opponent has to discard a card
• It’s an opponent’s turn to discard a card

But in Italian, starting with Tocca a... is perfectly normal.

Here it means a card in a general, non-specific sense.

Because it uses the indefinite article una, it usually means:

• one card
• a card (not a specific named card)

In a game instruction, scartare una carta means discard one card.

If it were a specific card already known from context, Italian might use the definite article:

• scartare la carta = discard the card

In card games, yes, scartare is the standard verb for discarding a card.

Examples:

• Scarta una carta = Discard a card
• Devi scartare due carte = You must discard two cards

Outside games, scartare can also mean:

• to reject
• to throw out
• to rule out

So its exact translation depends on context, but with carta, discard is the natural meaning.

Usually in this expression, Italian uses tocca because the subject is not really I/you/we, but the impersonal idea of it falls to / it is up to.

So you normally say:

• Tocca a me
• Tocca a te
• Tocca a lui
• Tocca a noi

And in the plural:

• Tocca a Marco e Anna
• Tocca agli avversari

You may also see toccano when the grammatical subject is plural, but in the common turn-taking expression, learners should first remember the fixed pattern tocca a....

You can replace a un avversario with an indirect object pronoun, depending on who the person is.

Examples:

• Tocca a me scartare una carta = It’s my turn to discard a card
• Tocca a te scartare una carta = It’s your turn to discard a card
• Tocca a lui scartare una carta = It’s his turn to discard a card
• Tocca a loro scartare una carta = It’s their turn to discard a card

If you wanted to refer back to an opponent, you would more naturally keep the full phrase unless the context is already very clear.