Learn Hardcore German: Ohne genaue Planung gelingt das Projekt nicht. - Without precise planning, the project does not succeed.

German main clauses follow the verb-second rule. Whatever you put in the first position (here the adverbial prepositional phrase Ohne genaue Planung) occupies slot 1. The finite verb gelingt must then appear in slot 2. Everything else (subject, objects, adverbials) follows. So the order becomes:

Ohne genaue Planung (fronted element)
gelingt (finite verb)
das Projekt (subject)
nicht (negation at the end)

Why is there no article before genaue Planung, and which case is Planung here?

The preposition ohne always takes the accusative case. In general, you can drop the article to speak in a general or abstract sense:
• Ohne genaue Planung = “Without precise planning (in general)…”
If you wanted to refer to one specific plan, you could say Ohne eine genaue Planung (with eine in accusative).

Why does the adjective genaue take an -e ending instead of -er or -en?

Because you have an attributive adjective with no article before a feminine noun in the accusative. That triggers the strong declension, where the ending for feminine accusative is -e.
Pattern: Ohne + [feminine noun (Acc)] → genaue Planung

Why is nicht used to negate the sentence instead of kein, and why is nicht placed at the very end?

kein negates a noun that has an indefinite article or is countable (e.g. kein Auto, keine Bücher). Here we’re negating the action/result (“the project doesn’t succeed”), not denying a noun with an article—so we use nicht.
In German, nicht that negates the entire clause or verb phrase normally goes late in the sentence, often right before or after other verbal elements. In our example it sits at the very end to cover the whole proposition: “the project does not succeed.”

What does gelingen mean exactly, and how is it different from verbs like schaffen, funktionieren, or erfolgreich sein?

gelingen (intransitive) means “to succeed” or “to turn out well,” focusing on the outcome of an action or plan.
schaffen can mean “to manage” or “to accomplish,” often emphasizing the actor: Ich schaffe es, “I manage it.”
funktionieren means “to function/work” (like a machine).
erfolgreich sein literally means “to be successful,” but it’s less idiomatic when you want to stress that a process or plan itself turns out successfully.

I’ve learned that gelingen often takes a dative object (e.g., Mir gelingt es). Why isn’t there a dative pronoun in this sentence?

There are two common patterns with gelingen:

Impersonal: Es gelingt mir, literally “It succeeds for me.” Here mir is dative.
Personalized subject: Das Projekt gelingt – now das Projekt is the subject, and there is no need for a dative person. We simply say “the project succeeds.” That’s why you don’t see mir or dir here.

How would I express the same idea as an infinitive clause? Can I say Ohne genau zu planen gelingt das Projekt nicht?

Yes, you can use a zu-infinitive clause:
Ohne genau zu planen, gelingt das Projekt nicht.
– You need a comma before the infinitive clause at the front.
– Both versions are correct; the noun version (Ohne genaue Planung) is a bit more formal/abstract, while the infinitive version sounds more dynamic.

Could I rephrase the sentence as Das Projekt gelingt ohne genaue Planung nicht? Would that be correct?

Grammatically, yes: Das Projekt gelingt ohne genaue Planung nicht.
– The subject Das Projekt now occupies slot 1, gelingt is slot 2, and the adverbial ohne genaue Planung follows.
However, many native speakers instead say:
Das Projekt gelingt nicht ohne genaue Planung.
– This moves nicht directly before the prepositional phrase, emphasizing that “it is not the case that the project succeeds without precise planning.” Both are understandable; the latter is the more common emphasis pattern.