A natural consequence of the ongoing process of democratisation over the last two centuries has been the increase of importance of the rules that influence the way we choose representatives rendering power in the name of the sovereign that is the nation. The fundamental role is played here by electoral systems, which in modern democratic states based on the rule of representative democracy determine the way of gaining and legitimizing power. Taking into consideration their great weight the question arises whether these particular ‘game rules’ themselves have an influence on the respect of the rule of law, being one of the basic norms of a democratic system.1 In other words – do the rules of the electoral law influence the scale of power abuses, which are committed by politicians holding public offices who are chosen according to these rules, and to what extent? A question then may be posed about the existence and the character of the relation between electoral systems and the level of political corruption, indicated in the title of this chapter.

The notion of corruption is here confined to the abuse of power by people holding public offices in order to gain undue advantages.2 It needs to be noted, however, that this phenomenon may be and frequently is defined more broadly – the notion of corruption may also apply to instances of abuse of the professional or social function fulfilled by representatives of other professions, e.g. doctors, university teachers, policemen or office workers, as well as – which by economists is taken into account extremely rarely – entities working in the private sector (Adit 2003; Jain 2001; Lewicka-Strzałecka 2001; 2007).

The evidence of the difficulty in defining the term on the legal and legislative level may be the verdict of the Polish Constitutional Tribunal from June 23rd, 2009 overruling part of the regulations of the Central Anticorruption Bureau Bill from June 9th, 2006. By act of this law the provisions determining in which situations we deal with the phenomenon of corruption included, inter alia, in this very act were declared not consistent with either the Constitution of the Republic of Poland, nor the Convention for the Protection of Human Rights and Fundamental Freedoms (Article 1 point 3 of the initial text of the bill). After the verdict taking effect the statutory definition of corruption expanded greatly.