EDIT: sorry, to clarify: one determines the utility for a possible choice by summing over the results of all the possible algorithms making that particular choice. (ie, "I don't know if my decision corresponds to deciding the outcome of algorithm A1 or A2 or...") so sum over those for each choice, weighing by the probability of that being the actual algorithm in quesiton)

I'm afraid that edit confused me more than it clarified. I can think of plenty of games for which that sort of utility calculation may be necessary but I can't see one made one explicit in the post. The way to handle this kind of uncertainty varies depending on how the other agents (Omega's or the possibly uncorrupted clones for example) are wired.