UMON

Fallout 3 gameplay
UMON

The UMON ("Usage Monitor") Base Effect is a hard-coded effect which tracks the consumption of addictive Ingestibles. When included in the effects of Ingestible which has an Addiction Chance and an Addiction Actor Effect, it allows repeated usage of the Ingestible to increase the odds of addiction.

Gameplay

In addition to standard addiction chance, certain items have an additional tracker value which builds up with each subsequent use of a substance. Internally, this effect is referred to as the "Usage Monitor Effect," or "UMON." Each use of an item adds its UMON value to the total UMON value and remains a part of it until its specified time limit elapses, at which point it is removed from the current running total. The accumulated value of 75 seems to equate to an additional 1% chance (added on top of any existing addiction chance), whereas a value of 175 seems to be equivalent to a 100% chance.

Duration

Duration is the length of time required to pass without consuming the drug for the accumulated UMON value to be reduced.

ITEM	CLASS	RISK	DURATION	UMON	WITHDRAWAL EFFECTS
Buffout	Chems	10%	30 hours	30	-1 EN, -1 ST
Jet	Chems	20%	30 hours	30	-1 AG, -1 CH
Ultrajet	Chems	20%	48 mins	12	-2 AG, -1 PE, -1 ST
Mentats¹	Chems	5%	30 hours	30	-1 IN, -1 PE
Beer	Alcohol	5%	N/A	N/A	-1 AG, -1 CH
Vodka	Alcohol	10%	N/A	N/A	-1 AG, -1 CH
Wine	Alcohol	5%	N/A	N/A	-1 AG, -1 CH
Psycho	Chems	10%	30 hours	30	-1 EN, -1 PE
Med-X	Chems	10%	30 hours	30	-1 AG, -1 IN
Scotch	Alcohol	10%	N/A	N/A	-1 AG, -1 CH
Whiskey	Alcohol	10%	N/A	N/A	-1 AG, -1 CH
Ant Nectar²	Chems	5%	1 hour	20	-2 ST
Nuka-Cola Quantum	Food	10%	48 mins	12	-1 CH, -15 Radiation Resistance

¹Only applies to plain Mentats, the other variations (Berry Mentats, Orange Mentats, and Grape Mentats) are nonaddictive.

²Only applies to plain Ant Nectar, the other variation (Fire Ant Nectar) is nonaddictive.