Related Clues:

• It turns 19 into 21
• Common wild card
• Occasional wild card, in poker
• Number two, at the casino
• Likely loser in war
• 0—0
• The two on dice
• A two in playing cards
• The two in playing cards
• In 35 across, it's an advantage to follow this
• After this, someone will have the advantage (5).
• Someone will gain the advantage after two such
• 1 down without twenty, it seems
• It might be wild at a poker table
• Small spade, maybe