Answer: wildcard

AnswerCrossword Clue
WILDCARD

A deuce used as an ace, say

WILDCARD

Joker

WILDCARD

Unpredictable one

WILDCARD
Unpredictable factor
WILDCARD
A deuce used as an ace, e.g.
WILDCARDDeuce, sometimes
WILDCARDDeuce sometimes
WILDCARDPostseason tournament pick