When I was putting together my potion description charts I had a fun (for game masters anyway) idea. Many of these potions could be locked away for years or even hundreds of years… so could these potions expire over time?
Sure, through magic one could say they stay potent forever. But it is more fun to say that while they last a very long time, they can expire causing the potion to:
- Have no effect.
- Have a diminished effect.
- Have a heightened effect.
- Have a strange side effect.
- Be poisonous. (Note that this “little bit of fun” for the GM doesn’t and shouldn’t cause a “save or die” situation, so the poisonous effects listed here are limited.)
A poor alchemist can also explain why a potion (even one just brewed) might not have the expected results.
Before getting into the random charts, depending on your game system, consider giving characters a chance to notice that a particular potion has expired and may have no effect or have a side effect or especially that it may be poisonous. This can be accomplished through an Alchemy or Spellcraft skill check or an equivalent in your game system.
Determine if the potion has an altered effect.
(You may wish to alter the percentages based on age of the potion or the location where the potion was found.)
| d100 |
Normal or Expired Effect |
| 1-2 |
Expired and poisonous. See the “Poison Effects” chart. |
| 3-4 |
Expired and it only has a strange effect. See the “Strange/Side Effects” chart. |
| 5-6 |
Expired but it simply has no effect. |
| 7-10 |
Expired but it still has 1/2 the expected result. The GM should adjust the effect by changing the duration, amount healed, etc. For example: the invisibility lasts only one hour instead of two hours or only 1d4+1 hit points are healed instead of 1d8+1. |
| 11-12 |
The potion acts as expected, but has a side effect. See the “Strange/Side Effects” chart. |
| 13-95 |
The potion acts as expected. |
| 96-00 |
Strangely the expired potion proves to be more effective. The duration is doubled or the healing is doubled, etc. |
Poison Effects
See the “Effect Duration” chart below to determine how long the effect will last.
| d12 |
Effect |
| 1-5 |
A physical ability score or equivalent (GM’s discretion) is reduced by 20%. (Note: this can not result in death through a rules side effect such as lowered hit points due to a lowered constitution-like score.) |
| 6-9 |
1 Limb is paralyzed (1d4: 1=left arm, 2=right arm, 3=left leg, 4=right leg.) |
| 10 |
Blindness. |
| 11 |
Deafness. |
| 12 |
Subject becomes mute. |
Strange/Side Effects
See the “Effect Duration” chart below to determine how long the effect will last.
| d12 |
Effect |
| 1 |
Subject’s skin tone changes. (1d6: 1=blue, 2=Green, 3=Orange, 4=Purple, 5=Red, 6=Yellow.) |
| 2 |
Subject’s eyes glow. (1d6: 1=blue, 2=Green, 3=Orange, 4=Purple, 5=Red, 6=Yellow.) |
| 3 |
Rapid body hair growth. |
| 4 |
Subject loses sensation of taste. |
| 5 |
Subject loses sensation of smell. |
| 6 |
Subject remains drunk. |
| 7 |
Subject feels itchy. |
| 8 |
Subject talks in a very high pitch or very low gravelly voice. |
| 9 |
Subject sweats profusely. |
| 10 |
Subject sneezes for half a minute every 5 minutes or so. |
| 11 |
Subject becomes very thirsty. |
| 12 |
Two side effects: Roll twice more. |
Effect Duration
| d6 |
Duration |
| 1-2 |
5 minutes |
| 3-4 |
1 hour |
| 5 |
10 hours. |
| 6 |
1 day. |
[...] you like random charts, there are a lot of them here at Inkwell Ideas: random potion descriptions; charts of effects of expired potions; random location names based on various languages (UK English, Chinese, Indian, Native American) [...]