The gambling game was clearly a setup to scam him out of his money.

setup 是由动词短语 set up 合并而成的名词，set 意思是"设置"，up 表示"向上、完成"。setup 在这里指"预先安排好的骗局或陷阱"，带有负面含义，表示精心设计的圈套。