Das Kartenspiel wirkt einfach, doch der Spieleabend dauert lange.

In German, the last part of a compound noun determines the grammatical gender.

• das Kartenspiel = das Spiel is the final element, so the whole noun is neuter
• der Spieleabend = der Abend is the final element, so the whole noun is masculine

So even though both are compound nouns, they have different genders because their head nouns are different.

wirkt is the 3rd person singular of wirken.

In this sentence, wirken means something like:

• to seem
• to appear
• to come across as

So Das Kartenspiel wirkt einfach means the card game seems simple or looks simple.

This is a very common use of wirken when talking about impressions:

• Er wirkt müde. = He seems tired.
• Das klingt gut, aber es wirkt seltsam. = That sounds good, but it seems strange.

Because einfach is being used as a predicate adjective, not as an adjective directly before a noun.

Compare:

• das einfache Kartenspiel = the simple card game
  → adjective before the noun, so it gets an ending
• Das Kartenspiel wirkt einfach. = The card game seems simple
  → adjective after a verb like sein, werden, or wirken, so it does not get an ending

This is similar to English:

• the simple game
• the game seems simple

Here doch means something like:

• but
• yet
• however

It introduces a contrast:

• Das Kartenspiel wirkt einfach
  vs.
• der Spieleabend dauert lange

So the idea is: it seems simple, but the game night lasts a long time.

Important: doch can have many meanings in German depending on context. Here it is a coordinating conjunction expressing contrast.

Because the sentence joins two main clauses:

• Das Kartenspiel wirkt einfach
• doch der Spieleabend dauert lange

In German, when two independent main clauses are connected by conjunctions like aber, doch, or denn, a comma is normally used.

So the comma helps separate the two full statements.

No—doch here is a coordinating conjunction, so it does not force the verb to the end or change the normal main-clause word order.

That means the second clause still follows the usual verb-second pattern:

• der Spieleabend = position 1
• dauert = position 2
• lange = rest of the clause

So:

• ..., doch der Spieleabend dauert lange.

This is different from subordinating conjunctions like weil or dass, which push the verb to the end.

Compare:

• ..., doch der Spieleabend dauert lange.
• ..., weil der Spieleabend lange dauert.

In standard German, lange dauern is the usual and idiomatic expression for to last a long time.

Here lange functions adverbially, modifying the verb dauert.

So:

• Der Spieleabend dauert lange. = The game night lasts a long time.

Learners often expect lang because English uses long, but German normally prefers lange in this expression.

You will often see:

• Es dauert lange.
• Die Reise dauert lange.
• Das Meeting dauert nicht lange.

German compound nouns are not always built in a perfectly predictable way. Sometimes the first element appears in a form that looks like a plural or linking form.

Here:

• Spiel = game
• Spieleabend = game evening / game night

The -e in Spiele- can be understood as a plural-looking form or linking element. It suggests an evening involving games in general, not just one single game.

German has many compounds like this, and they often need to be learned as whole words.

Both are in the nominative case because they are the subjects of their clauses.

• Das Kartenspiel wirkt einfach.
  → das Kartenspiel is the subject
• Der Spieleabend dauert lange.
  → der Spieleabend is the subject

That is why the articles are:

• das for neuter nominative singular
• der for masculine nominative singular

Yes, in this sentence aber would also work:

• Das Kartenspiel wirkt einfach, aber der Spieleabend dauert lange.

Both mean but, and both are natural here.

A small nuance:

• aber is the most common straightforward word for but
• doch can sound a little more literary, pointed, or elegant in some contexts

But for many everyday situations, they are very close in meaning.

Yes, German allows that, because German word order is flexible as long as the finite verb stays in second position in a main clause.

So you could say:

• Einfach wirkt das Kartenspiel, doch der Spieleabend dauert lange.

This is grammatically correct, but it sounds more marked or stylistic because einfach is being emphasized.

The original sentence is more neutral and natural for everyday use:

• Das Kartenspiel wirkt einfach, doch der Spieleabend dauert lange.