That is, characters doing frivolous stuff like drinking too much ale at the tavern and getting drunk. Spending gold to see a minstrel show. Gambling and brawling. Patronizing the local house of ill repute. Splurging on a lavish meal. Activities which real adventurers or soldiers would do in real life after surviving a harrowing adventure, but which a D&D player hoping to maximize XPs or gold earnings wouldn’t consider. By “encourage” I mean mechanics that use either a carrot or stick approach to prod PCs.
For me in particular, maintaining suspension of disbelief in an adventure is important. That means characters aren’t just monster killing machines but do believable things that add color to the adventure. I’m not saying players need to roleplay all of these activities; a simple die roll to check if a character is wise enough to steer clear of the whorehouse would work. If he doesn't make the die roll he's out 1d8 gp. (Although if the PC is a country bumpkin who's never been to the big city, maybe there would be an XP reward for doing crazy stuff at least once?) I’m limiting the discussion to adventure themed activities that are potentially fun – so for example having a picnic or falling in love and getting married probably isn’t something players want to simulate in a game even if it is something “real people” might do.
I’m interested in D&D v3.5 and Pathfinder rules, as written or homebrewed, but rules from other versions or even other RPG systems that can be easily ported into D&D are welcome. I suppose I could come up with rules on the fly, but I'm hoping someone's already thought of this and has tried and true rules that are consistent, intuitive, and of course fun. 🙂
Best Answer
The simplest and most common (it's part of many D&D retroclones) is to let "wasted" money convert to XP in some way. This hugely encourages spending it on things that otherwise give no advantage (carousing, careless gambling, anonymous church donations), while balancing it against the desire to use that coin for practical advantages. This balance ("do I throw a party for some bonus XP or do I buy a batch of healing potions?") adds an enjoyable layer of strategising to the game. A variation on this is to have the XP be "banked": it's not immediately available, but is added to the starting XP of the player's next character, as a kind of death insurance policy. Yet another variant in campaigns with XP costs for magic item creation or when cheating death, the bank can be used to pay these XP costs instead of the XP a PC is currently "using" to maintain their level.
Not everyone enjoys this though: players who keenly feel the need to make optimal choices may pull their hair out at the idea that they can't do both and have to choose. This will largely depend on your group's play focus preferences.
It also alters the dynamic of resources in your game: you may see a divide between PCs who go for more XP and those who go for more gear, resulting in a divergence of levels and of situational-readiness. This works in those other editions of D&D and in their retroclones because they are built in such a way that level and gear disparities are non-issues (a 1st-level can adventure with 8th-level PCs), but will not work if you and your group's campaign structure rely on PCs advancing in tandem.
Despite the caveats, when it fits a campaign structure it works well: players do react to the incentive to spend their coin on ephemeral frills, which are sometimes fun to roleplay and can establish character even when not. You will see some characters who are conservative and eschew the partying, and others who break the bank every time they come home with a good haul.