5,000 g.p. and a system shock roll, followed by two weeks of no-adventuring and no-spellcasting. Pavel spent the downtime casting Continual Light onto rocks. (And also finding deserving families to hold onto his share of the hoard before he went in search of the lost city of Hutakaa. (In Swahili, Hutakaa means “You will not stay.” Hmm. Prolly coincidence.))
We, the players, also talked about what a world changer continual light should be. Streets and houses should be lit up just like in our modern day real world. Dungeons might look more like shopping malls.
One of the great luminaries of our hobby would chide me for being a DM who wants to "crock magical effects he's not competent to deal with" and there are plenty of people eager to agree with him. Here are some of the "reasons" why continual light rocks are not a world changer:
• They’re inconvenient to extinguish when you want to sleep (no bushels)
• They cost 500 g.p.! (The DMG says so!)
• The thieves’ guild likes things shadowy and so they steal them all and hire magic-users to extinguish them so that they go back later and pick people’s pockets. (This is why they all still live with their moms.)
• People stay up a little later, so what, they still need heat.
• It would be a sacrilege. (This one had a really nice description of a Greek Orthodox festival featuring special candles that “people don’t use in their privies.” )
The last two are ok, except that a world where every family who lives within a couple miles of a parish church should have a little niche in their home where they keep a little glowing icon. Of course they still need fire for cooking, and they don’t (necessarily) throw their glow sticks into holes to see whether they contain coins or snakes—but they are a prominent feature of life. And the village priests who won’t hand them out are as lonely as the adventuring-priest who won’t use his cure light wounds on party-members who torture goblins.
My thought. Magic is almost by definition something that cannot be predicted. Cleric magic (miracles!) maybe even more so. God(s) made the world in a particular way and don’t allow it to be futzed with except for particular reasons. Continual light works when a cleric is going into the dungeon because he or she is going to do battle against the forces of evil. It is both a practical and a spiritual aid. In the village or the city, people just need to huddle together around their fires and talk about how to invent electricity.
Minor wrinkles to figure out: can Pavel cast continual light on lots of rocks while safe in his room in anticipation of going into the dungeon? If Pavel creates a continual light rock while in the dungeon, can he bring it back and give it to someone to hang up over the bar? Major wrinkle: If people are getting murdered in a particular alley, isn’t that serious enough to warrant a continual light spell? Wait, is this theology class?
Ultimately, I guess whether we speak of the gods of tough-love or the thieves’ guild photophobia, it’s really just a matter of one's preferred flavor of DM-ex-machina. Right?