Nie zaczynamy rozgrywki, dopóki każdy nie przeczyta instrukcji.

Because Polish often uses the genitive after a negated verb.

Without negation, you would normally get:

• zaczynamy rozgrywkę
• przeczyta instrukcję

With negation, these become:

• nie zaczynamy rozgrywki
• nie przeczyta instrukcji

So both nouns change because both verbs appear with nie.

This is one of the most common things English speakers notice in Polish: negation can affect the case of the direct object.

It looks like double negation from an English perspective, but in Polish this is normal.

After dopóki, Polish very often uses nie to mean until:

• dopóki nie przyjdzie = until he/she comes
• dopóki nie skończę = until I finish

So dopóki każdy nie przeczyta instrukcji means until everyone has read the instructions.

This nie does not mean that nobody reads them. It is just part of the standard Polish pattern dopóki nie + perfective verb.

Przeczyta is the 3rd person singular form of the perfective verb przeczytać.

Perfective verbs in Polish do not normally have a true present meaning. Their present-looking forms usually refer to a future completed action.

So here przeczyta means something like:

• will read
• will finish reading
• has read by that point

That is why it fits the sentence: the game starts only after the reading is completed.

Because the sentence is about completion, not just the activity itself.

• czytać = to read, to be reading, to read in general
• przeczytać = to read through, to finish reading

The sentence means that starting the game depends on everyone finishing the instructions. That is why przeczytać is the natural choice.

If you used czyta, it would sound more like ongoing reading, not reaching the end.

Because każdy literally works like each one / each person, so grammatically it is singular.

That is why the verb is singular too:

• każdy przeczyta

This is very similar to English in a sentence like everyone is ready, where everyone also takes a singular verb.

Also, when każdy stands on its own like this, Polish uses the masculine singular form as the default grammatical form.

Nie zaczynamy is present tense, but it often expresses a rule, habit, or standing procedure:

• We don’t start the game until...

That sounds natural if someone is explaining the rules of the situation.

If you wanted to talk about one specific future occasion, you could also say:

• Nie zaczniemy rozgrywki, dopóki każdy nie przeczyta instrukcji.

So:

• nie zaczynamy = general rule / usual practice
• nie zaczniemy = one concrete future event

Yes, you often could.

• gra = game, the general word
• rozgrywka = a play session, match, round, or actual instance of play

So rozgrywka sounds a bit more specific, like the session you are about to begin. In many contexts, especially board games or competitive games, it works very well.

You could also say:

• Nie zaczynamy gry, dopóki każdy nie przeczyta instrukcji.

That would also be natural, just a little more general.

Yes.

You can say:

• Dopóki każdy nie przeczyta instrukcji, nie zaczynamy rozgrywki.

This means the same thing. The difference is mainly emphasis.

• Starting with Nie zaczynamy... puts the focus first on not starting
• Starting with Dopóki... puts the focus first on the condition

Polish word order is flexible, so both are fine.

Because dopóki introduces a subordinate clause, and in Polish subordinate clauses are normally separated by a comma.

So:

• Nie zaczynamy rozgrywki, dopóki każdy nie przeczyta instrukcji.

And if you reverse the order, the comma still stays:

• Dopóki każdy nie przeczyta instrukcji, nie zaczynamy rozgrywki.

This is standard Polish punctuation.

Almost.

In many everyday sentences, dopóki and póki can be used with little or no change in meaning:

• Nie zaczynamy rozgrywki, póki każdy nie przeczyta instrukcji.

Póki is a bit shorter and can sound slightly more conversational. Dopóki can sound a bit more neutral or careful. But both are common and correct.

Yes.

You could say:

• Nie zaczynamy rozgrywki, dopóki wszyscy nie przeczytają instrukcji.

That is also natural.

The difference is:

• każdy = each person, emphasis on individuals
• wszyscy = everyone / all of them, emphasis on the whole group

Grammatically, that changes the verb too:

• każdy nie przeczyta → singular
• wszyscy nie przeczytają → plural

Both versions work well.