Spider Climb: choose targets and preserve concentration

SRD 5.2.1 · Spell decisions

Before casting

At the table

1. Touch one willing creature for the ordinary level-2 casting.
2. The target can traverse vertical surfaces and ceilings with hands free, and gains a Climb Speed equal to its Speed.
3. Maintain Concentration; a slot above level 2 permits one additional creature per extra slot level.

Example decision

A caster uses a level-4 slot and can touch enough willing creatures. How many targets does this casting allow?

Three targets: one base target and two additional targets.

Level 4 is two levels above the spell’s base level of 2. The higher-slot clause adds one target for each of those two levels, giving three total. It does not say to replace the target count with the slot level, double the climb speed or extend the concentration duration.

Watch for this mistake

Hands-free climbing is not a general immunity to falling or the loss of the spell. Track Concentration and any other effect affecting movement before planning a ceiling route.

Ask the table

How many willing touched targets fit this slot, and what could interrupt the caster’s Concentration?

Source spell

Level 2 Transmutation (Sorcerer, Warlock, Wizard) Casting Time: Action Range: Touch Components: V, S, M (a drop of bitumen and a spider) Duration: Concentration, up to 1 hour Until the spell ends, one willing creature you touch gains the ability to move up, down, and across vertical surfaces and along ceilings, while leaving its hands free. The target also gains a Climb Speed equal to its Speed. Using a Higher-Level Spell Slot. You can target one additional creature for each spell slot level above 2.

Source: SRD 5.2.1, 164. Online guide.