  Security properties are often focused on the technological side of the
system. One implicitly assumes that the users will behave in the right way to
preserve the property at hand. In real life, this cannot be taken for granted.
In particular, security mechanisms that are difficult and costly to use are
often ignored by the users, and do not really defend the system against
possible attacks.
  Here, we propose a graded notion of security based on the complexity of the
user's strategic behavior. More precisely, we suggest that the level to which a
security property $\varphi$ is satisfied can be defined in terms of (a) the
complexity of the strategy that the voter needs to execute to make $\varphi$
true, and (b) the resources that the user must employ on the way. The simpler
and cheaper to obtain $\varphi$, the higher the degree of security.
  We demonstrate how the idea works in a case study based on an electronic
voting scenario. To this end, we model the vVote implementation of the \Pret
voting protocol for coercion-resistant and voter-verifiable elections. Then, we
identify "natural" strategies for the voter to obtain receipt-freeness, and
measure the voter's effort that they require. We also look at how hard it is
for the coercer to compromise the election through a randomization attack.
