The corrupt dragon longsword was released on 15 October2008 along with the PvP worlds. It is the strongest longsword available to Free-to-play, but it crumbles to dust after 30 minutes of wielding. It requires 60 Attack to wield.
Players can obtain this item either by trading with another player, or by receiving it as a very rare drop from killing Revenants or the Chaos Elemental.
When a player is killed with a newly degraded version of this weapon, roughly half of the Grand Exchange market price is dropped instead of the longsword. It's a good method to get a partial refund of the weapon's price as you cannot trade the degraded version.
The corrupt dragon longsword does not require completion of the Lost Cityquest to wield.
Warning: Once you wield this item for longer than a few seconds, it will have the word (deg) added to its name and it becomes untradeable. Using this item in combat adds the (deg) to its name almost instantly, also rendering it untradeable.
As 30 minutes contains 3000 ticks, you are able to hit 600 hits with this sword before it crumbles into dust. Thus, each hit landed using this longsword is worth approximately 98 coins.
Although the regular dragon longsword was changed on 28 July2009, the corrupt version was not changed until later. The current version is now almost identical to the non-corrupt version except it is darker.