Skullduggeries are secret and dishonest activities or trickery.
Skullduggeries are usually thought of as bad or sneaky.
Examples:
The detective uncovered the skullduggeries of the criminal gang.
She was involved in all sorts of skullduggeries to win the competition.
The skullduggeries of the evil wizard were finally revealed.
The cat's skullduggeries to steal the food were always foiled by the dog.
The skullduggeries of the villain were so evil, they seemed like something from a story.
The skullduggeries of the politicians were so bad, they were in the news every day.