Table 1 

Pay – off matrix for predator and parasite strategies. 

parasite 
predator 



Mild 
Virulent 
Tolerant 
Resistant 



parasite 
Mild 
1y 
fr(1y)+(1fr)(1x) 
m 
p* m 
Virulent 
fr(1x)+(1fr)(1y) 
(1x) 
v 
p* v 

predator 
Tolerant 
y 
x 
z 
(1fr) p *z + fr *z 
Resistant 
 p * y 
 p* x 
(1fr)*z + fr (p* z) 
p* z 



The table differs from payoff matrix tables for classical game theory models. The table accounts for two alternative strategies each for two different types of players namely parasite and predator. The payoff of the parasite is not only decided by other parasites but also by the predator strategy and viceversa. Therefore the complete payoff of a mild parasite invading a virulent population in a tolerant host population is m * [fr(1y)+(1fr)(1x)]. Others to be calculated similarly. 

Jog and Watve BMC Ecology 2005 5:3 doi:10.1186/1472678553 