A proof of concept from many moons ago resurfacing as a comment that I was going to reply to and thought may better serve as a post.
This in reply to 
So without any thought, I am going to write the first thing that comes into my mind about a Hive Poker game without smart contracts.
Sounds like a plan.
Make a web page that lets up to 6 people play a hand of poker, maybe Texas Hold 'Em. There is a lobby and if there are more than 6 people in it, then there could be several 6 player hands happening at the same time.
Texas Hold 'Em would most likely be the game of choice. Would suggest maximum ten player table. Players may sit in and play with as few as two players, which would effectively be heads up. Players could be sitting at the table, taking up a seat, but be sitting out. Sitting out would need to be an option so players may take a break and keep their seat. This is standard. Many little nuances to take into account and code in. Imagine there may be some code to use as a template for (poker) game flow.
The hand is about to start. Players send X amount of HBD ante to the
account (which doesn't exist but I should make it real fast!). Everyone pays the same X amount, and there can be different leagues or something where X varies. Maybe some have X of 0.001 and others where X is 1 or whatever.
"Players send X amount of HBD ante to the
Players would send a (table) game buy in. Maybe taking $0.05 / $0.10 blind game as an example with a (maximum) $10.00 buying (100 Big Blinds). Could have a minimum buying of maybe as little as 40 Big Blinds, $4.00. Minimum bet would be $0.10+ by the $0.01. Raises would have to be coded in and what not in the poker game logic. May find a good example another time.
Random cards are dealt according to the standard game rules, People bet according to standard rules, maybe with a bet cap based on an ante multiplier. At the end, someone wins and
Matter of how random should be handled. Game likely to be No Limit in this case limited by game rules and player stack sizes. The game would keep track of player balances during the hand. Winnings would not be sent until player(s) cash out their winnings and choose to be done playing and leave their seat. Players' balance ("chips") should remain in play during the game and subsequent games.
Or maybe players could bet up to the stack size of $10.00. Provided players have X in their account and do not send it elsewhere during the game. This would require checks. Players should state how much they want to buying for and noted in this case and method of handling bets.
I'll think about it more, but seems like this might work.
Something could work. There have been some poker leagues on Hive so am sure there is some level of interest. Unsure if it may be fully worth exploring with such challenges.
Could possibly have a token for rewards for playing and dev work, managing, etc. Feels very in the form of a rake. This is about 4 to 5% up to a certain cap.
A token for take back rewards pooled with part of the rake may be found rewarding for players.
