Oil, why can't Monks use it? Beating a man to death with your bare hands is perfectly acceptable, but setting his ass on fire is somehow wrong? I never really got that, particularly in light of the fact that it is perfectly acceptable for Paladins to do so. So it can't be a "Lawful" thing. Whatever.
Oil is also one of those commodities I really need to track better in a dungeon setting. So far the players have been doing a pretty good job and I have been kind of faking it when they haven't, but it's a habit I really need to get back into.
Flaming oil grenades have also been a favorite tool in my daughter Ashli's arsenal, regardless of what character she has been playing, ever since she took an Ogre out by one-shotting him with a nearly impossible shot with a Molotov Cocktail into the darkness when she heard him coming. Thrown grenade-like missile, outside the visual radius of their campfire; her fighter had all kinds of negative modifiers to hit. Her plan actually had been to hope to start a fire somewhere near enough to it to illuminate it for the rest of the party to see and shoot at, but a natural 20; which in my campaign house rule always doubles the number of dice you roll for damage if you need less than a 20 to hit; combined with maximum damage absolutely incinerated his ass instantly.
O is for Ogotai, the Steppe Warrior name of my old buddy Darryl C. Ogotai was the first Khakhan of the Steppe Warriors and he had a pretty good, if relatively brief, run. He took my notes and wrote them into a pretty damned good guild charter; we tinkered with it a lot over the years, but the basic structure remains the same to this day. He made a better general than he did a politician and a better advisor than he did a leader.
O is for Oriental Adventures, hands down the most awesome expansion to the core AD&D rules. How awesome? The OA book sits on my desk next to my DMG, PH and MM. D&DG, FF, UA, MM2, WSG, and now DSG got to sit out on the bookshelf with the other RPG books*. Sure, you needed the other core books to play Oriental Adventures, that's not the point, it was never intended to be a "stand alone" version of AD&D; but it was the best setting book ever published by TSR. I loved the Original 1st edition Oriental Adventures from TSR. I kind of tried to make due with the disappointing 3e version from WotC; I house-ruled it back to a D20 version of the TSR version, but that was a lot of work and some people really didn't like my changes and modifications to core concepts, for the classes and races especially. I ditched Rokugan and ran with Kara-Tur because I was familiar with it and I had a lot of good times there. The 3e Oriental Adventures book with it's wholesale adoption of the Rokugan setting and consequent abandonment of Kara-Tur gave me such a hateful grudge against Legend of the Five Rings that it has taken me until now to get over it; and I was all about it previous to that because I thought that Clan War looked cool as all get out. I was never going to play the CCG, but that pretty much goes without saying about any CCG. I was largely unaware of the RPG until it's setting and rules trumped D&D's in a D&D product. I never really got the point of dumping Kara-Tur either, it's officially part of the Forgotten Realms, which is a giant cash cow for whoever owns the D&D product line. Kara-Tur may not be the most popular part of the Realms, but I am sure a lot of people would have paid for an update.
*OK, there is also an extra DMG, OA and a couple of extra PHs out there too; the point stands though, I keep them handy at my desk as a ready reference.