I play a lot of underground poker in NYC, and have thought a lot about optimal strategy in these games.
Key factors:
1) The games are much much looser than a casino, with considerably more fish.
2) The games play much bigger, due to frequently crazy rules (5x straddle on the button anyone?), large/uncapped buy-ins, and general insanity.
3) The rake is insane. Typical rake at a 5/10NL game is 10% capped at $35.
4) There are bonuses for starting the game. At the game in #3, for example, I can get $100 just to show up.
What are your thoughts about adjustments to these game conditions?