Macky888:
Let me give you the answer. I may not be 100% right. I am just 99.99999% correct.
The Common Gaming Houses Act (CGHA) is a must read to better understand laws governing gaming offences in S'pore.
A place is deemed as a CGH if 2 conditions are met. Gaming must be HABITUAL. No one in authority has defined what 'habitual' means. Not even Yong Pung How. Is thrice a week, each session 3 hrs considered more habitual than twice a week, 7 hrs each session? Hahahaha. No answer. Can police mount observation if the said gaming house is inside an office or a big bungalow? Can the police actually see or hear what is happening from outside the premises? Not possible.
A place is deemed a CGH if it is accessible to members of the public. If the gambling den is located in Geylang or a holiday chalet, hotel, flat, apartment, funeral wake etc and anyone can walk in, it means it is a gambling den. If your poker game is amonst friends, you have not committed an offence under the CGHA. Can strangers enter your house to play poker?
Other key factors to consider in differentiating a common gaming house and one that is not involves the "organisational structure" in place. If you play at home with friends, there is no structure. If it is a gambling den, you have the "kiao tau" followed by your hor lis, ma tows, drivers, "soldiers", look-outs, ah soh to cook and serve drinks etc. When you gamble in such places, you don't win full all the time. The den takes a cut of the winnings. They depend on these winnings to pay their staff on a daily basis.
The games you gamble on also determines if you are involved in illegal gambling. No undeground dens are invloved in games like poker, ginrummy, thor tai tee, blackjack, mahjong etc. Illegal dens only keen on fast games like si ki puay and pai kow. These are not games of social interaction.
About a decade ago, the CGHA was amended to allow certain games to be played at certain places. For instance, clans, associations, cooperatives etc were permitted to play games with social interaction as the key purpose. Si Ki Puay and Pai Kow are not allowed.
Hope the picture is much clearer now. If the police don't want to or can't explain, you can look for me. Cheers.