Ladder

My Grandfather used to call the game “Ladders and Adders”. He liked to apply whimsical labels to things. At his house, we switched channels using the “diddlebox” and things ran on “electrickery”. His especial pleasure was to use a term for the first time, when he could watch us trying to work it out. Revealing the meaning was as good as a punchline. I thought of him now. Was this an opportunity - a ladder - or was it an adder?