Corruption
The decent into Hell is not an easy one - it takes its toll on both the body, and he mind. But the ancient evils that dwell in this place are enough to change you, in body, mind, and even soul. It may turn you mad, it may disfigure you, and it can even turn you against your friends and loved ones with its lures.
Corruption is an optional rule that can be applied to the game. It has both system and story mechanics that can change the style of game you play. Certain items automatically impact upon this system, as well as any actions that you, the DM, feel can contribute aswell. For example, harming an innocent NPC, or making deals with the creatures in the Cathedral depths.
Corrupted Items
Certain items found in the Cathedral depths are flagged as "Corrupted", which will be stated in their descriptions. These items contribute to a player's corrption only once. Once this has been applied, it cannot be applied again, or to another player, unless a player has not yet become Corrupted.
It is up to you to, as the DM to announce these items as "Corrupted" or not. There is no way to remove the Corruption on these items.
Forms of Corruption
There is three forms of corruption in Diablo: Decent into Hell; Bloodlust, Madness and Decay. Each from of Corruption works in different ways, and affects players in unique ways. Once a player has been affected by one type of Corruption, they cannot be affected by another, but they can still accrue corruption scores from that source.
Bloodlust. The smell of blood becomes sweeter, the sounds of flesh tearing becomes music to your ears. You no longer desire talk, and negotiation, they only get in the way of what you really, truly want. From now on, you only take your steak bloody.
Madness. You swear that statue just winked at you. No-one else believe you, but since it's now laughing at you, it can't be denied. The others tell you that you're seeing things, but you know the creatures in this place are telling you things, things that only you can understand.
Decay. Your bones creak as you walk, your joints ache and your skin is drying out. moving is becoming harder, but the cold no longer bothers you. Sleep no longer comes easily, but then again, you don't feel you really need it anymore anyway.
Corruption Mechanics
If you use this mechanic in your game, every act can contribute to each player's corruption counter. Each player is responsible for keepting track of their assigned Corruption form, and their Corruption scores. When a player reaches a new tier in the Corruption scale, they gain the effects stated below.
Tier 1
When a player reaches 10 points, they must alter their ability scores, based on their assigned corruption. Read the appropriate alteration to each player
Bloodlust. Increase your Strength by 2, and decrease your Charisma by 2. Your muscles are beginning to swell and bulge in a grotesque form, and you no longer enjoy conversation. Your thoughts are always wandering back to the thoughts of battle.
Madness. Increase your Wisdom by 2, and decrease your Intelligence by 2. Your gaze is always shifting, jumping from shadows that flicker in the corner of your eye, to statues in the shadows.
Decay. Increase your Constition by 2, and decrease your Dexterity by 2. You have become thin - noticeably so. Almost skin and bone. Moving has become harder, your joints have become stiff and sore.
Tier 2
When a player reaches 20 points, they must alter their ability scores, based on their assigned corruption. Read the appropriate alteration to each player
Bloodlust. The smell of blood is intoxicating. Once per day, you can consume blood of any creature, other than yourself, to recover d10 hitpoints, plus your Constistuion modifier.
Madness. The walls have begun talking to you. Once per day, you can communiate with any inanimate object - statues, chairs, or dead creatures, and ask one question about the current floor of the dungeon.
Decay.
Tier 3
When a player reaches 30 points, they must alter their ability scores, based on their assigned corruption. Read the appropriate alteration to each player
- Bloodlust.
Madness.
Decay.