Alternative uses of Spider Climb

Question

During my group's recent run of White Plume Mountain in 3rd Edition, we encountered a scenario that brought into question the versatility of the Spider Climb spell effect. In the dungeon, one room involves a trap in which the floor is "magically frictionless", and the group is bound to slide around helplessly into traps. One player, however, tried to reason that he could use his Slippers of Spider Climb to help.

(There actually are Slippers of Spider Climb available to be found inside the dungeon as treasure, but by coincidence, the player already had their own pair. Nevertheless, the dungeon designers may have actually considered this.)

The reasoning is that a floor is not physically different than a wall, simply at a different angle. By crawling on all-fours, the adventurer should be able to activate the ability and stick to the floor just as they would a wall, moving at the typical 1/4th speed. As the DM, I allowed this clever use.

This got us thinking: What other uses does the Spider Climb spell have? How far does this ability to stick to things actually stretch? Using this logic, it would seem that it would grant a considerable benefit to balance checks in most situations where one might be thrown about. Granted, they would have to be prone for this to work, and most balance checks are done to avoid becoming prone, defeating the purpose in those cases. Still, scenarios where someone might need to keep their balance from being flung in a direction, such as staying on a boat in a storm, or holding on to a rampaging colossal creature, may apply.

Answer 1

As a matter of fact, Spider Climb does not allow to traverse frictionless surface automatically, much as the spiders can't traverse glass, for example. All it does is granting climb speed to its subject, and that doesn't even mean automatic climb success:

A creature with a climb speed has a +8 racial bonus on all Climb checks. The creature must make a Climb check to climb any wall or slope with a DC higher than 0, but it always can choose to take 10, even if rushed or threatened while climbing. If a creature with a climb speed chooses an accelerated climb (see above), it moves at double its climb speed (or at its land speed, whichever is slower) and makes a single Climb check at a -5 penalty. Such a creature retains its Dexterity bonus to Armor Class (if any) while climbing, and opponents get no special bonus to their attacks against it. It cannot, however, use the run action while climbing.

Still, climb skill could be used to traverse horizontal surface

With a successful Climb check, you can advance up, down, or across a slope, a wall, or some other steep incline (or even a ceiling with handholds) at one-quarter your normal speed. A slope is considered to be any incline at an angle measuring less than 60 degrees; a wall is any incline at an angle measuring 60 degrees or more.

but in the case of "magically frictionless" surface skill check will either receive penalties (-5 for slippery surfaces, I'd suggest at least -10 in the magical case) or be outright impossible (if it is also perfectly smooth).

Note: creatures with climb speed moves at its full climb speed while climbing, or at double that (but not greater than its base land speed) while performing accelerated climb.

Answer 2

As always, uses of spells beyond the "letter of the law" are at GM discretion and are largely based on your approach to the game (gamist, simulationist, narrativist). My group likes the realistic-world approach and so we do allow spider climb to have additional affects like this. It's not sovereign though - if you get whipped hard enough on a ship's mast you're going off; the GM sets a reasonable bonus to the Climb check/Balance check/CMD check/whatever's relevant. In Pathfinder, our 3e variant of choice, Spider Climb says:

The subject can climb and travel on vertical surfaces or even traverse ceilings as well as a spider does. The affected creature must have its hands free to climb in this manner. The subject gains a climb speed of 20 feet and a +8 racial bonus on Climb skill checks; furthermore, it need not make Climb checks to traverse a vertical or horizontal surface (even upside down). A spider climbing creature retains its Dexterity bonus to Armor Class (if any) while climbing, and opponents get no special bonus to their attacks against it. It cannot, however, use the run action while climbing.

So a +8 bonus to anything you'd allow a Climb skill for would be fine, and I'd let a Climb check stand in for Balance etc. if you're flat and gripping with hands and feet. Often in game the distinction between a Balance check, Reflex safe, Dex check, Climb check, etc. is somewhat amorphous. If the PC has time to brace themselves in "all fours" I'd generally allow using the spider climb-enhanced Climb check in situations where it made sense.

Answer 3

Spider climb is better than a climb speed

The affected creature must have its hands free to climb in this manner. The subject gains a climb speed of 20 feet; furthermore, it need not make Climb checks to traverse a vertical or horizontal surface (even upside down).

But climbing smooth surfaces is impossible

(from table)
— A perfectly smooth, flat, vertical surface cannot be climbed.

but for Epic climbing rules

The character can climb otherwise unclimbable surfaces.

A perfectly smooth, flat, vertical surface [is DC] 70
A perfectly smooth, flat, overhang or ceiling [is DC] 100

Since spider climb permits climbing without making checks, those DCs would be immaterial, allowing a spider climbing creature to traverse glass, ice, greased walls or ceilings, etc., because climb also says

Surface is slippery (increases DC by 5).

Spider climb thus allows movement along virtually any solid surface.

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The slippers won't cut it

The frictionless floor might be climbable due to the spell, but Slippers of Spider Climbing's description says:

Severely slippery surfaces—icy, oiled, or greased surfaces— make these slippers useless.