The steam obscures even infravision. The
party must cross the chasm in some manner
even though they are unable to see. The
steam will continue to fill the chamber for
5 turns and then will clear for 1 turn. If
the party waits for the steam to clear, someone
will undoubtedly be caught crossing
when the steam returns.

The edges of both ledges are weak and
crumbling, and cannot be climbed either up <Climb, SG>
or down. Anyone falling into the chasm will
suffer 3-18 points of damage and will be <6d6 damage: Falling, SG>
impaled by 0-2 stalagmites, causing 1-6 <2d6 damage per stalagmite>
points of damage each. The only nonmagical
way across the room is to use the
pinnacles as stepping stones.

Naturally the stones are slippery from the
steam in the air. For any person to leap from
stone to stone, he must roll equal to or less
than his Dexterity on 1d20 for each jump <Jumping, WSG>
(6 leaps in all). Of course, he must 1st
determine where each stone is, by feel or
some other method. If the party strings a
rope across the fissure, add +2 to the Dexterity <Crossing a Chasm on a Rope, DSG>
roll and only roll once for each character
crossing. If the party returns to room 12
and gets the 4-foot boards, they discover
that the boards just reach from pinnacle to
pinnacle. Using the lumber adds +3 to the
Dexterity roll and characters need only roll
once. These 2  bonuses are cumulative.

>>15.