The spell of knock, if cast at a container while Skilled or Expert, should disarm any trap on the container. However, this breaks the consumable-renewable principle (a spell that costs 5 Pw being a free untrap for containers is powerful), so maybe it should be given to the wand of opening instead, and to avoid it being better than the invoke power of the Master Key of Thievery, it should still set off the container trap.

Casting knock at a tree should behave as though you kicked the tree. Not specified whether a wand of opening should also do this, since it doesn’t have “knock” in the name.

Some ways to scale some spell effects with skill. Generally, this consists of nerfing unskilled and basic casting rather than adding even more powerful high-skill effects.

• Beam spells such as knock and wizard lock scale the range of their beam with skill, with only a few squares at Unskilled, up to 4 squares at Basic, up to 6 at Skilled.
• Identify always identifies exactly 1 item when Unskilled.
• Light scales its radius with skill.
• Charm monster only pacifies 1 monster at Unskilled, and can only tame 1 monster at Basic, 3 at Skilled, no cap at Expert.

The spell of knock cannot be used to escape from an engulfer (the wand of opening, however, still can). Casting knock into an engulfer produces the message “You knock on the inside of [monster], but nothing seems to happen.”

Change the Rogue’s special spell to knock rather than detect treasure.

In variants that have the Pirate role, this would free up the spell of detect treasure to be their special spell.

When a door is hitten by an opening beam, it actually opens, rather than becoming unlocked. Also, any doors adjacent to it will also be opened (for the “double doors” that appear in some special levels).

Remove the spell of knock entirely in favor of the wand already being a good enough source of opening magic.

Nerf the spell of knock in comparison to the wand of opening: it should be a melee-range spell (or a beam with range 1), and possibly it can’t be used to open containers until you are at least Basic in matter spells.

Zapping an opening beam at a closed, unlocked door opens it. Casting knock at Skilled or Expert lets you unlock and open all at once.

Hitting a statue with a wand of opening (possibly the knock spell too, but it might be nice to let the wand have a fringe benefit) causes it to drop all its contents without breaking.