Historical Rules · 11 November 2016
Rule 210.1
Official source text from the 11 November 2016 Rules release
Each vanguard card has a hand modifier printed in its lower left corner. This is a number preceded by a plus sign, a number preceded by a minus sign, or a zero. This modifier is applied as the starting hand size and the maximum hand size of the vanguard card’s owner are determined. See rule 103.4.