I bought a computer Monopoly game about a decade ago, and I remember one of the options was to negotiate immunity deals with your (computer) opponents. I found this to be the one surefire way of always winning.
Yeah. My house rule is that anyone suggesting we play Monopoly gets roundly mocked before we go play a game that isn’t terrible.
I just want to say that I have lived an extraordinary life. I have never, ever played a game of Monopoly using house rules, unwritten rules, this-is-the-way-we-play-it-here rules or anything like that.
Of course, that sometimes led to endless, unwinnable games. At some point, we’d just throw the dice and all the little houses and hotels back in the box and walk away.
Someone really ought to link to this Straight Dope column:
What is supposed to happen when you land on “Free Parking” in Monopoly?
Maybe someone will eventually.
If anyone would like to try your hand at Monopoly by the book rules against up to three computer players, go here: Monopoly
A game against three other players usually takes an hour or so.
That’s about right. I still like Monopoly. All you Carcasonne and Settlers of Catan folks can just fuck right off. 
And I don’t understand the “endless, unwinnable” games playing by the rules. Between 14 and 16 years old my friends an I must have played about 300 games of Monopoly. I never remember a single game going beyond two hours; most were finished in 60-90 minutes.
The official rule that many ignore, lengthening the game, is that if a player doesn’t want to or can’t afford a property he lands on, that property is to be auctioned off to the highest bidder.
That’s the official rule I like the least. I enjoy having no free parking rule and paying interest when you unmortgage a property, but it seems quite enough to build in enough of a bankroll to afford properties you happen to land on, let alone properties other people land on that they can’t or won’t buy, and all of that on a random schedule.
Was this an official Monopoly game, or just one of the many clones?
The official NES game allowed you to offer properties and cash, so that’s how I knew that trading properties was officially okay. If an official Monopoly game allows immunity, then I’d think that the non-tournament rules allowed it.
But I do like the idea that, since the game has no rule to enforce agreements after the fact, there is no way to enforce immunity. There’s a critical difference between contracts that are instantaneously filled, where you physically cannot renege, and contracts that occur at the same time.
Doing it the former way is how you enforce contracts without laws that force the issue, and allows you to make deals with known swindlers. Instantaneous contracts are, in effect, self enforced.
In high school we played Monopoly with three boards connected together corner-to-corner, so there were three different Boardwalk deeds, distinguished with colored paper clips. There was a 4th board called the Debtor’s Colony; bankrupts could go there and hope to get enough money to get back in the main game. We also had insurance companies and private banks and, IIRC, municipal elections. Yes, the game was interminable, but the game was just backdrop anyway: we used the get-togethers to plot revolution and, perhaps, to flirt with the two girls who had strayed into our clique by accident.
To me immunity is grounds for forfeiture due to ‘no game’. The game simply doesn’t allow these things to happen, if they do your not playing the game. Note this is different from penalties which are allowed by game rules(we see this all the time in sports like football where a penalty sometimes taken intentionally.
I went through this years, no decades ago. We came to the conclusion that no you can’t give immunity, additionally informal partnerships are still partnerships and is grounds for the forfeiture of the game. The rule is that rent must be paid. About that part that the owner must ask for payment, which quite honestly didn’t come up back then), I believe the spirit of that is if you accidentally miss that payment you are SOL, but intentionally ignoring it (which would be defacto if the any player announces that they are owed rent) is a partnership and thus grounds for forfeiture on the grounds that a player is not following the rules and thus no game.
Any partnership would be about the same as rerolling the dice because you didn’t like the rule, it’s not allowed and grounds for calling the game.
As for house rules, I believe much of the reason for them was monopoly is not really suited for children, and rules to soften the harsh reality of the game had to be put in place. * Once those children grew up then they carried forth those rules, and the hippy movement started, free love and sexual revolution . JK *