Learn French: Pourvu que le parieur trouve son ticket ! - Let's hope that the bettor finds his ticket!

Normally, pourvu que connects two clauses and means 'provided that'. But when placed at the start of a standalone exclamation like this one, it expresses a strong wish or hope, translating to 'Let's hope that...' or 'If only...'.

Is trouve actually in the subjunctive here? It looks exactly like the present indicative.

Yes, it is the subjunctive! For regular -er verbs like trouver, the present subjunctive forms for je, tu, il/elle/on, and ils/elles are identical to the present indicative. Even though it looks the same, it is grammatically in the subjunctive mood because pourvu que demands it.

Could I just use J'espère que to express this hope?

You absolutely can, but the grammar changes. If you use J'espère que, you must use the indicative mood (often the future tense for hopes), like this: J'espère que le parieur trouvera son ticket. Using Pourvu que instead adds a slightly more anxious or intense feeling, like 'Let's just hope that...'.

What verb is the noun parieur related to?

It comes from the verb parier, which means 'to bet' or 'to wager'. The -eur ending is commonly used to turn a verb into the noun for the person performing the action, much like the '-er' suffix in English.