This starter deck is pretty effective at winning against King Elmer III via manipulation of his Plus/Combo rules. Use this to get some powerful cards early on.

Watch this video (credits: ObiDougKen0bi/YouTube) for effective strategies and orders to follow for number manipulation:
"Triple Triad: Defeating King Elmer III w/ Starter Deck"
https://youtu.be/prkU76Mhm3g