Fig.: to imitate someone; to follow someone's example

The European countries recognized the independence declared by the Baltic Republics and U.S.A. is expected to follow suit in a few days

I paesi europei hanno riconosciuto l'indipendenza dichiarata dalle repubbliche baltiche, e si pensa che gli Stati Uniti faranno lo stesso entro qualche giorno

When the big department store announced a 30% drop in its prices, the other big stores immediately followed suit

Quando il grande magazzino ha annunciato una riduzione del 30% sui prezzi, gli altri grandi magazzini hanno fatto subito altrettanto

This phrase originates from card games like bridge and whist, in which one must play a card of the same suit as the one that was led.
A clear example of the figurative use of this expression can be found in a letter dated December 4, 1766: “The great duty of conversation is to follow suit, as you do at whist."