Spellweb covered up to maximum of 70 cubic feet (2 cubic meters) with a sticky web. The web needed two diametrically opposed anchor points, otherwise the web collapsed and disappeared on casting.
The web glowed with a green light that faded to white over time. At the caster's discretion, the web could be created without giving off light. Another option was to create a web that gave off a pearly light.
The web was easy to ignite. A candle could burn away the spellweb in one minute. This was of course dangerous for people stuck in the web. While it was burning, the web gave off smoke. This smoke was harmless except that it limited vision.
Web and caster maintained a mental link. This link made it possible for the caster to sense when the web was disturbed, damaged, or had simply expired. A sufficiently strong cleric could end the spell prematurely.
When someone touched the spellweb, the person was stuck fast at the web. Sufficiently strong and/or big creatures could break through the web but their mobility was still inhibited.
Creatures stuck in the web were easier to hit. However, ranged attacks were not an effective way to attack someone stuck in the web.
Spellweb required somatic and verbal components. Its material components were a holy symbol and a crystal of any size. This crystal did not need to be an expensive one like a diamond or even an inorganic one like salt, as a piece of sugar was also a viable crystal.