Monopyly
A Python framework to allow AI algorithms to compete at playing Monopoly
This project is maintained by richard-shepherd
Making Deals
Monopyly has a simplified deal-making protocol which allows players to trade properties with each other and which allows cash to be included in the deal.
I suspect that there is a bit of a prisoners-dilemma involved in the decision about whether to make deals or not. AIs that do not make deals will, I think, lose against AIs that make them, as the ones that make deals will be more likely to gain complete sets of properties. On the other hand, there is a strong incentive not to offer too good a deal to an opposing player, and this may result in deals not being made at all. Getting the balance right between these extremes will be one of the challenges in writing a good AI.
Proposing deals
Towards the start of your turn, you are given the opportunity to make deals. The propose_deal() method will be called three times to let you do this. A deal proposal consists of these parts:
- 'propose_to_player': the player (Player object) you propose the deal to.
- 'properties_offered': a list of Property object you offer to the player.
- 'properties_wanted': a list of Property object you want from the player.
- 'maximum_cash_offered': cash you are willing to pay as part of the deal.
- 'minimum_cash_accepted': cash you want as part of the deal.
Either 'properties_offered' or 'properties_wanted' can be empty lists (or None) but they can not both be empty. At least one property must change hands as part of a deal.
You specify either (but not both) of the maximum-cash-offered or minimum-cash_accepted values.
Accepting or rejecting a deal
If a deal is proposed to you, the deal_proposed() method will be called on your AI. You see the properties proposed but you do not see the cash component. You can reject the deal outright. If you accept the deal, you can in turn specify the maximum cash you will offer or the minimum you will accept for the deal to take place. If the cash amount is acceptable to both parties, the deal will take place. The properties will be transferred, and an amount of cash midway between what is acceptable to both parties will change hands.
Example 1
Player 1 proposed a deal to Player 2, offering Vine Street and wanting Mayfair and offering up to £600 along with the deal. Player 2 does not see the cash component, and accepts the deal wanting at least £400. The deal will take place, and the properties and £500 will be exchanged.
Example 2
Player 1 proposed a deal to Player 2, wanting Kings Cross Station and offering up to £300. Player 2 accepts the deal, wanting at least £350. Because Player 2 wants more cash for the deal than Player 1 is willing to pay, the deal fails.