Whether Philippine President Rodrigo Duterte aims to shock, inspire or just amuse, deciphering his blunt and often unpredictable rhetoric is a potential challenge for investors seeking policy clarity from the new leader.

When it comes to the war on illegal drugs, events have unfolded the way Duterte promised, with more than 800 people killed in police operations since he was sworn in on June 30. On his pledge to invest heavily in infrastructure, Duterte has impressed overseas investors, who have pumped $1.1 billion into the nation's shares over the last three months.

But on a range of other issues, Duterte has sent more confusing signals. Some have been as innocuous as his choice of residence. Others have carried more weight, such as whether the Philippines intends to negotiate with China over territory in the South China Sea, or whether the country can live without mining, or if he really means to ban online gambling.