*2nd tier (terrain)*
**Challenge** 8 (3,900 XP); **DC** 17/15
**Area** Local (1 hour)
Gases bubble upon the marsh’s surface — the gas is poisonous at best and combustible at worst.
#### Realize Danger
Any adventurer that makes a [[03-Mechanics/6-Ability Scores/Nature|Nature]] check recognizes the prevalence and dangers posed by the marsh gas.
## Possible Solutions
A [[03-Mechanics/6-Ability Scores/Medicine|Medicine]] check and use of a [healer’s satchel](https://a5e.tabletopbytheik.nl/compendium/items/healers_satchel) (or a check made with tools the Narrator deems appropriate) can create a remedy to the poisonous gases, or a group [[03-Mechanics/6-Ability Scores/Survival|Survival]] check enables the party to carefully navigate the marsh.
**Critical Failure.** Travel time in the marsh is doubled, adventurers are poisoned for 4 (1d4+2) hours, and each takes (22) 4d10 fire damage from exploding gas.
**Failure.** Adventurers become poisoned for 2 (1d4) hours, and each takes 11 (2d10) fire damage from exploding gas.
**Success.** The adventurers safely cross the marsh.
**Critical Success.** The adventurers pass through the marsh safely without penalty or injury. Additionally, an [alchemist’s supplies](https://a5e.tabletopbytheik.nl/compendium/items/alchemists_supplies) or [poisoner’s kit](https://a5e.tabletopbytheik.nl/compendium/items/poisoners_kit) check harvests enough gas for 2 (1d4) vials of basic poison or explosive flasks (which function as [alchemist’s fire](https://a5e.tabletopbytheik.nl/compendium/items/alchemists_fire_flask), but deal regular fire damage instead of ongoing fire damage).