What are the most useful languages?

Depends. Is Common really all that common?

Undercommon -- if you're going, you know, down there. Or killing stuff from that area. If that area exists.

Draconic -- Language of Dragons, Lizardfolk, Kobolds and Wizards of all nations. Dragons love to hear themselves speak, so this is a good way to learn stuff and stay untoasted. Top of the list for my campaign. A good choice in a default setting game, too.

Celestial -- Language of Celestials (duh) and good priests of all nations. If you want to seem good, it's a great language with which to greet strangers.

Sylvan -- Language of Fey and some of the nicer monstrous humanoids (like Centaurs). Do you expect to see many Fey?

Abyssal and Infernal -- Two that would serve you well in my demon-haunted game. But seeing as most of the cool fiends have telepathy anyway, why bother?

Giant -- Trolls, ogres, giants. They come in large groups, and you can often reason with them. This is a good one.

Orc -- Who cares? It's an orc. Kill it.

Gnoll -- (see "orc" above)

Goblin -- Three types of goblinoids, and some DMs just love to give 'em class levels (like yours truly), so this might be a good choice. Depends on both the prevalence of goblinoids and the expectation of giving a hoot what they have to say (see "orc" above).

Dwarf and Elf -- You can pass notes that the Halfling can't read. Totally worth it.

Ignan -- DMs love fire critters more than all other critter types. Why is this? The answer is simple. It's because PCs are flammable. If you want to take an obscure language, this one will probably serve you best. Well, unless you're at sea.

So, my six choices would be:
- Celestial
- Draconic
- Dwarf
- Elf
- Giant
- Undercommon

Cheers, -- N

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