Champions

A champion always has a slightly better profile than the rest of their unit, most often an extra Attack (in a close-combat-focused unit) or an extra point of Ballistic Skill (in a shooting-focused one) -- some champions carry other characteristic bonuses too, shown directly on their own profile.

A champion model usually looks different from the rest of its unit, but always counts as carrying exactly the same weapons and armour -- unless its own Warhammer Armies book explicitly gives it access to equipment the rest of the unit can't take.

A champion shoots using its own characteristics, but must fire at the same target as the rest of its unit -- it's worth rolling its shots on a different colour of dice if its Ballistic Skill differs from the unit's.

A champion can never be targeted directly by enemy attacks, and can only be removed as a casualty once no other rank-and-file models (including the standard bearer or musician) remain in the unit -- so a unit of three models that suffers 3 or more unsaved wounds has its champion among the casualties.

A unit with a champion may re-roll a failed test to march despite nearby enemies, to reform, or to restrain from pursuit.