Code of Honor
±2 
but you cannot use other battle plans.
Q: If I’m the Chancellor and I’m joining a campaign as an Imperial Ally to a Citizen defender, does using this battle plan mean that the Citizen defender can’t use other battle plans?
A: Yes. This is an errata from the rules as written.
Q: If the bandits rule Code of Honor as well as other battle plans that they can use, which battle plans will they use when defending in a campaign?
A: They will use Code of Honor and no others.