Decision rules in Ms Pac Man

From a research project in Artificial intelligence where the researchers trained computers to succeed in playing Ms Pac-Man:

When the agent has to make a decision, she checks her rule list, starting with the rules with highest priority. In Ms. Pac-Man, ghost avoidance has the highest priority because ghosts will eat her. The next rule say that if there is an edible ghost on the board, then the agent should chase it, because eating ghosts results in the highest points.

One rule that the researchers found to be surprisingly effective was the rule that the agent should not turn back, if all directions are equally good. This rule prevents Ms. Pac-Man from traveling over paths where the dots have already been eaten, resulting in no points.

What are your heuristics? When are the rules of the game changing and are you changing your actions?