The Haunted Jar bonus round rule is one of the many rules that can be applied during the Bonus Round episodes. It is offered when either entering floor 4 or 5 as long as either of these conditions are met:

• Drake is the boss of the dungeon
• At least 2 of these 4 enemies are in the dungeon:
  • Haunted Jar
  • Drain Monster
  • Dire Wolf
  • Rat King

However, it won't be offered if the Slime bonus rule is active, since a constant amount of damage would be nasty to the player.

Haunted Jar

Poison is no longer reduced by 1 each turn.

When the rule activates, both fighters in each fight will gain a permanent innate status that makes it so that any Poison inflicted won't be reduced at the end of each turn. This means that means that any Poison inflicted will usually last forever, since equipment like Healing Crystal+ and gadgets like Emetic aren't often available or used to reduce Poison.

If the Drain Monster rule comes into play as well, you'll have to deal with being permanently Weakened as well, so try to avoid getting that rule.

• If the Warlock Bonus Round rule is also active, Parallel Universe Poison? will still reduce by 1 at the end of each turn.