Hiya!
Doug McCrae said:
How does one successfully combine sandbox and campaign play?
*shrug* I don't think I've ever had this problem. At least not in a few decades.
How do I do it? I run a rather harsh "old skool" style of game; the world
IS out to kill the PC's. I, the DM, am the "world", ergo
I am out to kill the PC's. That said, I am the world...so I don't really care one way or the other. Seems contradictory, huh? It isn't. When I DM I play the opposition as they would behave or be capable of based on a myriad of factors, most of which is "how tough does the creature
think it is... how tough the creature
actually is... how
intelligent is the creature with regard figuring out when it is in a situation falling to the first or second point". Alignment plays a big part. Good creatures will avoid or try and "end it quickly". Neutral creatures are primarily driven by survival vs. danger (a risk:reward thing). Evil creatures will try to hurt/kill things whenever they think they can get away with it.
Anyway...because my games are "deadly", wealth is usually one of those "It sure would be nice to find a thousand gold pieces!" things. They are usually thinking "But honestly, I'd just rather have something other than a loincloth, a rock, and 1/4 of a water skin traipsing around in this desert after being teleported by that eff'ing crypt thing!"
Wealth? Xp? Magic Items? LOL! Keep dreaming, newb! You're first level, expect to die horribly! If adventuring was easy, everyone would be doing it!
But if you don't run an old skool style campaign, I guess the only option is really to find out what each PLAYER wants to get out of the game, then see if it's something you would enjoy giving to them. I the Players really enjoy the mechanics side of thing, then money, equipment, magic items, 'unique' equipment/items, special training that 'breaks' the rules somehow, etc is where you'd go. If the Players really enjoy the thrill of the hunt, give them a multi-part adventure quest where each ending of a part reveils more of the puzzle and grand scheme of things. If the Players just enjoy the talking and roleplaying of it, give them special favours owed by powerful people or titles of office and things relating to the RP'ing aspect of their PC's.
I guess in short, it just relies on what the Players want. And if you don't know what they want...ask them. It really is that simple. (...or go hard-core old skool on their collective PC posteriors and just start littering the campaign landscape with the beaten and broken bodies of scores of characters...that works too...

).
As far as I'm concerned "Sandbox" and "Campaign" play is the same thing...from the perspective of the Players. They don't know (or at least
shouldn't) that X is going to lead to Y which will end with Z. My players know that when I whip out some old module or something, that it is the "starting point". How long the player pursue that 'adventure' is based entirely upon their desires. I have had players (somewhat often, actually...call it 30%) decide that they are "done" with some particular adventure area and just wander off to some location on the world map that they thought sounded cool. My last "Kingmaker" campaign (Pathfinder, by Paizo), the PC's did the first adventure...mostly. Just as they would have started into the second they went back to the Lord (Baron? Duke? I can't remember), handed their 'writ of passage and settlement', said "So long, and thanks for all the fish!" and then left the area, heading north to Red Dragon Mountains iirc (curious to see if there were actual red dragons there...silly Players!...they should know better by now!...). That did NOT mean the campaign "ended"; it only changed the story.
^_^
Paul L. Ming