Originally Posted by Wikipedia

Grass is a card game, first published in 1979 and now published by Euro Games and Ventura International (packaged in a hemp bag). The game is an expanded version of Mille Bournes with the theme altered from car racing to cannabis dealing. Many of the rules are essentially the same, with the cards altered as follows:

Distance cards are replaced by "peddle cards", indicating the sale of cannabis to a particular value. There are six types: Home Grown, Mexico, Columbia, Jamaica, Panama, and Dr Feelgood. Each of these has a different monetary value.

Hazard cards are replaced by "heat on" cards, indicating police activity preventing a player from obtaining cannabis: Bust, Detained, Felony, and Search and Seizure.
Remedy cards are replaced by "heat off" cards, indicating police activity has concluded: Immunity, Hearsay Evidence, Charges Dropped, and A Breeze To Fly.

Safety cards are eliminated.
The "green light" and "red light" cards are replaced by "market open" and "market closed", but the effect of these is different. In Grass, a player does not need to play a "market open" card after a "heat off" before they may again begin playing peddles; and "market close", rather than a hazard played temporarily on one player, can be played by any player to immediately end the entire hand.

In addition to the standard card types from Mille Bournes, Grass adds several new types:

Skim cards allow a player to steal peddle cards on the table from other players. Steal Your Neighbor's Pot allows the player to take any peddle card from another player, and The Banker allows the player to steal a percentage of every player's peddle cards at the end of the hand.

Protection cards allow a player to protect their peddle cards against skim cards. There are three types: Grab a Snack, Catch a Buzz and Lust Conquers All. They differ in the total value of cards they may protect. Dr Feelgood, the highest valued peddle card, may never be protected.

Pay Fine cards function as heat off cards, but require the player to sacrifice peddle cards on the table in order to play them.
Nirvana Cards give bonuses to players. There are two types: Stonehigh and Euphoria. Either of these cards will provide an extra turn and cancel any "heat on" card active on the player. In addition, the player receives a peddle card from every other player: Stonehigh requires players to hand over their lowest unprotected peddle, whereas Euphoria requires player to hand over their highest unprotected.

Paranoia Cards give penalties to players. Each of these cards imposes a penalty on the player who plays it. However, if the cards are found unplayed in a player's hand at the end of a hand, a score penalty is assessed: it is up to the player to decide which is worth less. Further, whenever any of these cards are played, each player may pass a card from their hand to their neighbor: this can allow the play of one of the less dangerous Paranoia cards to enable a player to pass on a more dangerous one.

Sold out forces the player to skip a turn and lose their lowest peddle; Doublecrossed forces the player to skip two turns and lose their highest peddle; and Utterly Wiped Out forces the player to skip two turns and destroys all unprotected peddle cards they have in play.