Learn Danish: Spillet er sjovt fordi vi prøver noget anderledes. - The game is fun because we are trying something different.

When you use an indefinite pronoun like noget (something), the adjective following it usually gets a neuter -t ending, like in noget nyt. However, adjectives that end in -s, like anderledes (different) or fælles (common), are exceptions and never add a -t.

Why is the adjective sjovt spelled with a -t here?

It has to match the noun it describes, which is Spillet. Since spil is an et-word (a neuter noun), the adjective sjov must take the neuter -t ending to become sjovt.

Could I say noget forskelligt instead of noget anderledes?

You could, but the meaning shifts slightly. noget anderledes means a change from the norm, like doing things in a different way. noget forskelligt usually implies various things or items that are distinct from one another. Since they want to try a new way to play, anderledes fits best.

If we wanted to add ikke (not) to the second half of the sentence, where would it go?

It would go right before the verb, making it: fordi vi ikke prøver noget anderledes. The word fordi always starts a subordinate clause, and in these clauses, small adverbs like ikke or altid must come before the verb rather than after it.