Keeping track of ammunition

I was just reading a Papers and Pencils article on stuff that never works in RPG's. That sounds like a challenge to me! One of the things on the list was limited ammunition.

Now, I understand that if your quiver holds scores of arrows, it's a lot of trouble to keep track of. You can't expect players to keep erasing and re-writing a number on their character sheets every six seconds of combat. But there's an easier way.

Every time a player rolls a natural 1 or 20 on their attack roll for a missile weapon, or any other weapon that involves keeping track of ammunition, have them make a tally mark in the margin of the character sheet. This is the trick. Not Arabic numbers, only tally marks, and no subtracting anything, only counting upwards. Tallying and comparing to another number is easier than subtracting. Divide the quiver's capacity by 10. This is the maximum number of tally marks there can be.

For instance, let's say you have an archer whose quiver holds 50 arrows. Then if, in the middle of combat, he reaches five tally marks (which looks like four vertical lines under a diagonal stroke, representing 50 arrows), he's run out. This is equally likely to happen following a hit (if you roll a twenty) or after a miss (if you roll a one). When you resupply, you just erase the tally marks and you're good to go again.

Of course, you might want to keep track of special magic arrows separately, one tally mark per magic arrow.

That's it. It's easy to keep track of this because natural 1's and 20's are special events (criticals and fumbles) that players are already on the lookout for. You don't need to remember a DC or make separate rolls for randomly running out.