I am absolutely confused about meaning of "blunt" here. Could not find any card game by this name, no idioms, nothing :( Thank you for you kind help.
Setting: London's gaming hell, 1833.
Nobody knows the real identity of club founder, known as Chase. The reward is offered. Members of the club are waiting for the reveal.
“And we have no doubt that very soon, one of you enterprising gentlemen will discover the truth about the founder of the Angel.” She paused. “Five thousand pounds is, after all, a great deal of money to a motley group that loses blunt so well.”
"Never Judge a Lady by Her Cover" by S Maclean