Historical Rules · 1 May 2013
Rule 311.7
Official source text from the 1 May 2013 Rules release
Each vanguard card has a life modifier printed in its lower right corner. This is a number preceded by a plus sign, a number preceded by a minus sign, or a zero. This modifier is applied to the starting life total of the vanguard card's owner (normally 20) to determine how much life that player begins the game with.