[RPG] What magic items can be used to trap/ensnare/capture enemies

Unfortunately, there are extraordinarily few effects that last past a short rest. There are extraordinarily few effects for a PC. However, the magic of 4e is that monsters do not use the same magic items, skills, or plot macguffins as a PC.

The most effective PC MacGuffin is the Executioner Assassin's Carrion Crawler Brain Juice. This Executioner only poison that takes the place of one of their daily powers:

Power (Consumable * Poison): Minor Action. You apply the poison to a single handheld object. Within the next hour, the first creature other than you to hold or wear the object for more than 1 minute is immobilized until the end of its next extended rest.

While this doesn't prevent teleportation, a Dimensional Anchor neatly solves that problem: Property: Any creature within 10 squares of this statue can’t teleport.

The act of applying this poison and the use of this statue, while effective and almost impossible for PCs to combat, completely destroys their agency. It is far more effective to get them in a "teleportation trap" (some sort of handwavy trap/almost-completed ritual) or equivalent instant transport that doesn't involve

"you put on your armor like normal, right?"

"Yeah...?"

"Okay, well, you're immobilized until you sleep next, which can't happen for another 16 hours."

A teleportation trap accomplishes the same thing, but doesn't actively interfere with the player's character's interactions with themselves and their own mental models.

First question: trigger

The character needs only to have at least one level of a class which can cast the spell. In this case a first level wizard will be able to trigger any wizard spell.

Second question: completion

From the SRD: Scrolls

To have any chance of activating a scroll spell, the scroll user must meet the following requirements.

• The spell must be of the correct type (arcane or divine). Arcane spellcasters (wizards, sorcerers, and bards) can only use scrolls containing arcane spells, and divine spellcasters (clerics, druids, paladins, and rangers) can only use scrolls containing divine spells. (The type of scroll a character creates is also determined by his class.)
• The user must have the spell on her class list.
• The user must have the requisite ability score. If the user meets all the requirements noted above, and her caster level is at least equal to the spell's caster level, she can automatically activate the spell without a check.

This means that the character must be a spell caster of the correct type (arcane or divine): so no a fighter will not be able to use a scroll.

If she meets all three requirements but her own caster level is lower than the scroll spell's caster level, then she has to make a caster level check (DC = scroll's caster level + 1) to cast the spell successfully.

In this case: yes a first level wizard will be able to try with any arcane scroll (if he has the required Int) but he will have to perform an appropriate caster level with the following consequences:

If she fails, she must make a DC 5 Wisdom check to avoid a mishap (see Scroll Mishaps). A natural roll of 1 always fails, whatever the modifiers. Activating a scroll is a standard action (or the spell's casting time, whichever is longer) and it provokes attacks of opportunity exactly as casting a spell does.

Use magic device

You can use this skill to read a spell or to activate a magic item. Use Magic Device lets you use a magic item as if you had the spell ability or class features of another class, as if you were a different race, or as if you were of a different alignment.

This allow to override the first condition: even if you are not of the correct class (or have the wrong alignment and so on) and you have the use magic device skill you can do a check and try anyway.

So in this case if your 20th level fighter is trained in use magic device: yes he can use a scroll