You can spend 10 minutes planning an encounter in exact detail. When you do so, you can share your plan with up to six Allies within 30 feet of you who can see or hear you and who can understand you. Each Ally that understands the plan can gain Advantage on an attack roll or ability check it makes within the next 10 minutes. If an Ally rolls Initiative during this time, it can't use this feature to gain Advantage after the end of the first round of combat.
Once you use this feature to make a plan, you can't do so again until you finish a Long Rest.