I posted way back a million years ago about playing a character who's main weapon was a shovel. Durn the Dwarf, bearer of the rune shovel died in a dismal cave. Talysman was running the game and in fine old school fashion when the dice said that Durn died that's what he did. I was thinking today that the shovel really is a top notch dungeon exploration weapon/tool. Maybe the western martial arts crowd would say that there's no room for such an unwieldy two handed weapon in a dungeon environment, but I think I'm not going to worry about that too much in a game where the dwarves who are famous for dwelling underground (in presumably tight quarters) are also famous for wielding big axes and hammers. What I mean is, in a world of 10' corridors it hardly seems like an issue. Though if the caves did suddenly get all realistically twisty and narrow what better than a trusty shovel to make a bit more room for the broad shouldered barbarian? If these games were realistic then dwarves and goblins would be crawling around in the dark in tunnels too small for humans and I doubt they'd carry much more than a shiv or two.
Ah but if your after realism then the shovel is the first thing your PC should pick up when spending their 3d6x10 gold! Let's look at a potential real world situation: Say you come across a rabid raccoon attacking your neighbors cat and you must rise to the occasion and intervene. What would you rather have a knife or a shovel? Are you going to bend over and take a stab at the raccoon? That would be rediculous, certainly far more dangerous and nerve wracking than being able to put the shovel between the two animals and if you had to be more forceful you could from a safer distance. Heck, I think in that situation a shovel would be preferred to a .22. You might hit the cat after all. Now, if this situation sounds like it has nothing to do with D&D, look at your preferred 1st level monster list. A lot of those creatures resemble a rabid raccoon! In size, temperament or both.
But a shovel is a ridiculous weapon you say? Let's look at the Level 1 Wandering Monster table. Of the 20 entries on the table 9 (almost half!) are monstrous creatures the shovel could be used to chop or swing at. These are creatures like the fire beetle and the spider crab as well as the aerial attackers: the killer bee , the sprite and the stirge. 10 on this list are humans or humanoids. They probably don't want to get whacked by a shovel either. That leaves the green slime. This type of creature is best prodded from a safe distance rather than attacked. Don't have a ten foot pole? A shovel will do in a pinch.
The Level 2 list breaks down similarly. Not until we get to the level 3 monster list does the shovel start to seem outclassed, but I think it's just an oddity of the popular imagination that a sword seems like it would do much better. Against these creatures you really need higher hit dice or a magic weapon or both. And if that's the case, then why not play a Dwarven Shovelmaster (3rd level) with a +1 Rune Shovel?
How about weapon restrictions? There isn't anything that prohibits a wizard or cleric from carrying a shovel is there? Is your wizard tired of striking Gandalf-esque poses while not actually doing much that is useful? Put a shovel head on that staff and get busy! My point is this: If you can walk into a dungeon with a magic missile spell memorized then certainly do so, but bring a shovel too.