poly-table

d4Affected Area / Amount
1Small / Few
2Medium / Several
3Large / Many
4Huge / Countless

Geological

d20Type
1Unstable ground
2Rockfall
3Earthquakes and tremors
4Volcanic fissures
5Concealed holes
6Quicksand or mud pits
7Sinkhole
8Fumaroles and gas vents
9Shifting sand dunes
10Lightning-filled storms
11Magnetic anomaly
12Razor-sharp crystals
13Tectonic rift
14Landslide or avalanche
15Acidic pools or rain
16Dust storm
17Blistering heatwave
18Frozen whiteout
19Eroding cliffside
20Flash flood

Flora and Fauna (Hazard)

d8Type
1Rabid animals
2Stampede / Panicked animals
3Poisonous animals
4Territorial animals
5Overgrowth
6Poisonous plants (contact)
7Poisonous plants (airborne)
8Magical / Unusual plants

Magical or Unusual

d8Type
1-2Ambush (Lair nearby)
3-4Disease
5-6Gas pockets
7-8Trap