Combat boost - temporarily boosts your Attack, Defence, Strength, Ranged and Magic levels by 5. Skill boost - temporarily boosts one of any non-combat skill excluding Agility by 2. Exploration boost - temporarily boosts your Agility level by 5. Note that other items providing a visible level boost, such as spicy stew or tea in a Player-Owned House, will not stack with the banner's effects. You can't drink the best tea (+3) and use a +2 banner boost to get a +5 Construction bonus - it will simply default to the stronger bonus or more recent negative modifier, in this case +3 for the tea.