Hankering for some Diablo 1, but most resources online only cover Diablo 2. Is there easy way to run it natively? Would old Mac emulation work in lieu of dual-booting Windows? Is Diablo 1 feeble enough to run well in virtualization? Should I virtualize Snow Leopard with Rosetta instead of Windows? What route has the highest chances of success?
You can't run it through a normal method.
Here is what I found:
Classic won't work since you're running an Intel. Diablo under Classic (on PPC) works poorly or not at all anyway, in my experience.
You can try SheepShaver. However: it can be confusing to set up (the linked directions @Xeem are pretty good); you need an OS 8 or 9 system folder/disc to run it (NOT downloadable from Apple); and it's pretty unstable for gaming in any case - this on my PPC, which runs it natively.
The Windows solution. Since the Battle Chest CDs are hybrids, you'll have a PC version to run. However, you'll have to buy a copy of Parallels/VMWare. Why not just do Boot Camp for free? Even then, you'd still need (have to buy?) a copy of Windows XP. A little pricey to run one old game.
Short answer: there's no one solution that's both easy and free, sadly.
I can understand why you'd want to play Diablo, though. #II has more choices, but seems to devolve into a constant flood of A. weak items for your class or B. great items for another class, requiring you to town-portal every 5 minutes to free up space. Diablo really had the formula down of streamlined dungeon crawling, nearly every item an improvement, and click-click-click gaming.
In this topic, they advise the person to try Diablo 2 instead, because it'll provide more choices to run.
Those are other two links that say more or less the same.
I would go with either VMWare (preferred) or VirtualBox. The game is very old and should have no problem running in a virtual machine. You should use Windows XP.
I think even Diablo 2 will run fine in a VM, but this always depends on the host system etc. A guideline is to use a system that is 10X faster than the requirement.
Sometimes graphic cards have problems with VMs, but both games do not need any graphics acceleration.
My personal experience is that you should invest some money in a good virtualization solution as the freeware tools do not support graphics acceleration. Still Diablo 1 should run fine in either.
I do not own a Mac, but a friend recently installed Age of Empires 2 in VMWare Fusion and we could play.