Mint
Will only be bought:
- according to what’s in the buy rules (so be very careful and add enough conditions so the Mint buy doesn’t destroy your deck)
Will only be played:
- if we have a Treasure in hand we want to Mint
When played:
- copy the best treasure in hand that player wants more of according to his buy rules
Geronimoo's Dominion Simulator 
This might need some fine tuning for hinterlands
Ill-Gotten Gains rush/thief(Plr 2)’s cards in Hand: [Silver, Mint, Copper, Copper, Ill-Gotten Gains]
Ill-Gotten Gains rush/thief(Plr 2) plays Mint
… Ill-Gotten Gains rush/thief(Plr 2) gains a Silver
Ill-Gotten Gains rush/thief(Plr 2) plays 2 Coppers
Ill-Gotten Gains rush/thief(Plr 2) plays 1 Silver
Ill-Gotten Gains rush/thief(Plr 2) plays Ill-Gotten Gains
… Ill-Gotten Gains rush/thief(Plr 2) gets +$1
Ill-Gotten Gains rush/thief(Plr 2) has $5 to spend and 1 buy
Ill-Gotten Gains rush/thief(Plr 2) buys a Ill-Gotten Gains
Ill-Gotten Gains rush(Plr 1) gains a Curse
Ill-Gotten Gains rush/thief(Plr 2) draws 5 cards
Ill-Gotten Gains rush/thief(Plr 2)’s cards in Hand: [Ill-Gotten Gains, Curse, Copper, Silver, Copper]