For an always-drunk NPC, you have a number of options.
First, simply "de-level" an NPC of higher level, to represent the overall poor effects of being drunk.
In a more complex mode, have the monster be 2 levels higher than the appropriate monster for the level, but impose the following conditions.
- Aura 1: [The NPC] and any ally in the aura grant combat advantage, due to [The NPC] pawing at them and slurring "help a 'fella out" and other phrases.
- Drunk: If [The NPC] starts his turn prone, he must make a saving throw or become dazed (save ends).
- Very Drunk: I f [The NPC] starts his turn dazed, he must make a saving throw or become stunned until end of his next turn.
- Dead Drunk: If [The NPC] starts his turn stunned, he must make a saving throw or be unconscious until at least the end of the encounter.
- Drunkard's Walk: If the NPC takes a move action, he must spend at least 2 squares moving in a random direction, then make a save or fall prone. [The NPC] may continue their movement, if possible, at this point. (If prone, they may crawl one square to complete their movement.)
- Immediate Reaction: An enemy or ally moves adjacent. [The NPC] must move 2 squares in a random direction and then save to fall down prone.
- Free Action: When struck by a critical attack: [The NPC] is stunned (save ends) as he starts vomiting.
Rules for Players
For players, drunkenness should be handled like a disease.
Every time they drink more than 3 drinks in an hour, they have to make an easy endurance check for their level (moderate or hard for very strong drinks).
For each failed endurance check, they progress one level on the "Drunken disease chart"
- Level 1: Grants Combat Advantage until recovery
- Level 2: If the player moves more than 2 squares during their turn, they must make a save at the end of their movement or fall prone. The player cannot shift while this drunk.
- Level 3: Roll a save at the start of turn or be dazed until start of next turn.
- Level 4: Dazed. Roll a save at the start of turn or be stunned.
To recover, they go up a level for every hour they haven't had a drink.
To find a list of potentially useful status effects to swap out in this chart, (especially for level 2):
- Go to the compendium
- choose: Search - Glossary,
- Category - Rules,
- Type: Rules Condition
- Click apply
Or go to page 277 of the PH1