The first and most important tool for running a game is paper. Or in this case, digital paper. Voila:
Exhibit A: Computer.
This crap-tacular laptop is an old Dell Latitude C600. It is my best friend on the gaming table, because it allows me to simultaneously DM and browse Facebook. I had to stick a wireless network adapter card into the side because it doesn't have that newfangled integrated wireless technology. Notebook PCs are getting cheaper all the time, so acquiring an old machine that does your basic grunt work is neither difficult nor very expensive. Of course, lacking this wonderful piece of technology, the rest of the toolkit should still do the trick.
Thing 2: Flip-Mat™.
A dry-eraseable, wet-eraseable Flip-Mat™ from Steel Sqwire is a great product to have on hand. It conveniently folds down to about the size of an 8.5"x11" piece of paper and fits into any folder or binder, but fully opened it provides a 22" x 28" playing area. I own too, and yet I was too lazy to take a picture of either. I did, however, take pictures of all the other items in my kit.
Item C: Haversack O' Dudes.
This bag of dudes, also known as my d-bag, contains miniatures of many varieties from which players can choose their characters. I think it's important to use miniatures for player characters, but for monsters I keep a ziplock bag full of plain black slotted bases of different sizes. This not only spares me having to cart around huge cases of miniatures for every conceivable baddie the party might come across; it also gives me the opportunity to simply put a base down on the table and describe the monster to the players. I can use a picture to show them the monster if I want, but describing their opponent instead of showing them a miniature lets the players use their imagination. What a concept, right? Or maybe it's just an excuse not to spend hundreds of dollars on miniatures...
Another Thing: Being Able to Write.
Once you have paper, a writing implement is the other half of the battle when it comes to pen-and-paper games. Contrary to popular theory, Knowing constitutes only about 3% of the battle, and not the 50% certain militaristic cartoons would have you believe. If you don't believe me, you should meet some of my players...
#5: Keeping Track of Your Players.
Since each gaming session is perfectly planned and no one has any other priorities in life besides gaming... ahem... players who aren't there will need to be lashed and keelhauled for their insolence. But that has to wait 'til next gaming session because they're not here right now to receive their punishment, and you need a way to run their character until that joyful moment comes. So I have my players fill out these little cards and update them periodically. The image at left is just clear enough to show that something's written, but too blurry to really make out what the hell it is. Sorry about that. I do know that this character's ID# is 69, which is hilarious and clever. Kinda.
#5b: Keeping Track of Your Players...
The task of keeping initiative order is made easier by writing that order down. But then you've got to scratch out and scribble every time someone holds their action or whenever a new group of enemies shows up. While these things only happen every so often, it's especially annoying to have to re-write the initiative order after you've kill one of those 'less-than-capable' characters. It's not like everyone else in the party doesn't resent them for always getting hurt and making them have to spend their action to use healing instead of dealing a wicked killshot to some kobold minion. So these delightfully hand-written note cards are nothing more than note cards with hand-written character names on them. Exactly, that's what she said.
Seven: The Tome of Convenient Evil.
I made this out of some 3x5 cards and a custom binder designed to hold them. As you can see (Vanna White pose) I also got some of those sticky tabs to divide up the sections. Compacted stat blocks fit easily onto these, so you can grab your own stuff from wherever and add it to your book so you'll always have it close by. GM's love creating custom NPCs and making up monsters (I mean come on, if you haven't already considered what a sweet bad guy a dude with the head of a chimera and the left arm of a griffon would make, can you honestly call yourself a real GM?) and I've found this to be a nice way of holding them all.
Eight + 9 = Gaming Aids.
A folder (8) with your maps, letters, and anything else you need to use as a handout can be slipped into the toolkit at a minimum of space. A cardboard DM screen (9) may also fit into the folder, and depending on your game system will save time looking things up in books. Still, you've got to have your books.
Don't sleep on these. Every good Game Master knows that the image below is supposed to be just generic enough to prevent system-specific alignment (and copyright infringement), but I don't think it achieves either of those purposes.
So there you have it, my Game Master Toolkit. If you have any other good thoughts on gaming ideas, equipment, or methods, keep them to yourself! Just kidding.