|A crowd of hopeful IDOC campers.
The premise behind an IDOC was that the player-placed structure was about to disappear from the game world leaving behind all of it's now unlocked items. Anything in the house was available for the taking from the bookshelves to the rarest of rare items from Ultima Online's past. Player's would camp out for days at IDOC houses (and the term houses is used loosely as sometimes they were actually massive castles). In the case of houses in the Felucca realm where open world PvP was allowed it was a blood bath as the time ticked nearer and nearer (and Felucca being the oldest realm in UO, it's collapsing houses offered the chance for the rarest loot).
After the loot was scooped up the real prize was yet to be had: one lucky person would get to place a new structure. This may seem insignificant in today's MMOs where there is an endless supply of special housing areas, but in Ultima Online's case there was literally not a single bit of land left to build on. There was far more players wanting to place a house than there were spots to place one. Placing a house after an IDOC was cleared out was a feat for the history books, especially when it was done in Felucca where there was a very real chance that the player would be killed and have their "house deed" stolen (which for a lot of players was a very expensive item to lose).
I can't claim to have ever "won" an IDOC. I was more of the opportunist when it came to IDOCs. I would take the time to make runes so players could portal/warp to the IDOC location. Becoming well known for finding IDOCs and not selling bogus runes to players meant good income. Then to opportune even more with the situation if the house was in Felucca it was time to bring out my sneak thief and pick pocket any of the campers visiting. Or if I was up to the task I could unstable an entire army of tamed dragons on my tamer and let them loose upon the camping crowds.
The IDOC is something I truly miss in today's MMOs. The idea of actually losing something; of the world actually changing. This is deep thought stuff that developers stand up on grand stages and get voracious applause for before they turn around and build another WoWClone in the background. MMOs will never return to their golden age, but the memories I formed in that time will never stop me from dreaming about them.