To splash in poker means to throw chips into the pot, often in a forceful way. It comes up in two main uses:
- If a player splashes the pot, it is difficult or impossible to ddetermine how much the player put into the pot, which makes it difficult to determine how much they are betting, or if they put in enough to call the bet to them. Thus, a player splashing the pot is breaking the rules and can end up receiving strong warnings from the dealer or floorman. In extreme cases, players may even be required to re-bet their bet amount if it truly cannot be determined that the player bet at all, or what amount they bet.
- If the house splashes a pot, this generally refers to a promotion whereby the casino chooses to add extra money into a single pot for some reason (usually due to some random draw). This amounts to an extra prize for the eventual winner of the pot and can often lead to significant extra action on the hand, since players may now be getting ridiculously high pot odds for all sort of unlikely draws.
The term splash comes from the colorful idea that the pot is a literal pot of liquid of some kind -- and throwing chips into it in a forceful fashion will cause the liquid to splash.