Il sistema elettorale è un complesso di regole che governano la traduzione delle preferenze in voti e dei voti in seggi (Rae 1971, 14) e, in quanto tale, costituisce al contempo un vincolo ed una risorsa per tutti coloro - elettori, partiti, candidati - i quali, a vario titolo, concorrono a determinare la rappresentanza politica. In altre parole, esso contribuisce a modellare la struttura delle opportunità di quegli attori, il tipo di competizione che prevale a livello del sistema partitico e, in certi casi, l'espressione stessa delle preferenze elettorali.
The essay examines the new electoral system introduced in Italy for the elections of the House of Deputies and the Senate. The goal is to describe the main features of the system and to identify the range of behavioral choices it offers voters, candidates and parties. The system is a mix between plurality and proportional representation: 75% of the seats, both in the House and the Senate, will be assigned with the former rule and the rest will be allocated proportionally. However, the two electoral formulas are not applied independently of each other, but there are instead a number of linkages between the two levels (particularly for the House). These linkages offer incentives to all actors in the game for calculating their optimal strategies. The paper aims at analyzing these strategic choices and the impact they might have on the structure of competition and the overall effects of the system. The paper focuses particularly on the new system for the House, given its greater complexity. The specific differences between the House and the Senate are treated in a separate section.