Learn Italian: Quali dadi devo tirare adesso?

Quale (which) works like an adjective here because it asks about the noun dadi (dice). In Italian, quale has to agree with the quantity of its noun. Since dadi is plural, quale changes to its plural form, quali. If you were asking about a single die, you would say Quale dado...

I thought tirare meant 'to pull'. Why does it mean 'to roll' here?

Tirare is a very versatile verb. While it often translates to 'to pull', it is also the standard verb for throwing, tossing, or rolling an object. Therefore, tirare i dadi is the natural way to say 'to roll the dice' in Italian.

Why isn't there an io (I) before devo?

Because Italian verb endings already tell you who is doing the action, subject pronouns like io are usually dropped. Devo specifically means 'I must' or 'I have to' (from the verb dovere). You would only add io here if you wanted to emphasize that I have to roll them, rather than someone else.

Could I use ora instead of adesso?