Traps for Vigilant Players?

Our friends-only server is playing a deathtrap game where we try to go the longest without dying, and the people who are dead can set traps to try and kill the living players (similar to Demise in Hermitcraft). I was unlucky enough to die first, and I am trying my best to make clever traps which can kill the other players.

Caveats:

• Only one player is rich enough currently to consistently afford a full set of enchanted diamond armor. Everyone else is stuck in iron.

• We haven't gotten to the End yet but are working on it.

• No access to command blocks, mods, or creative. We're vanilla Java 1.14.4 Survival with a few quality of life Spigot plugins.

• I want as little griefing done in players bases as possible because it feels bad destroying peoples' hard work and potentially their chests.

• Not everyone has the vanilla texture pack, and some have shaders (in case this was important since some pressure plates don't always blend in with planks).

• They are mega-paranoid about everything, and keep disarming the traps almost as soon as I put them down. I know it's the nature of the game to be vigilant but come on.

I've planted tnt minecarts under trees and floorboards, tried obvious fake traps hiding the real ones, and even planted one where destroying a pressure plate will set off the real trap. Nothing has worked so far and I'm running out of gunpowder.

If possible I'd like any death trap which can be well-hidden and simple enough for a redstone noob like myself to pull off without killing myself, not limited to explosives, which cannot be easily found and disarmed by the victim. I know this may be a tall order and not every trap is gonna work, but there's gotta be some trap designs out there to help with this.

Please help a desperate coyote out here. And, if you know how to build the trap in question, redstone advice would be greatly appreciated.

Solution 1:

A very simple trap that is virtually undetectable is the "landmine" you have carpet covering redstone ore and an observer observing the redstone ore. Then you hook the observer to a bunch of tnt and when the player walks over the ore (covered with carpet) it will emit particles which counts as a block change so the observer activates the tnt and blows the player to smithereens. (just make sure when you are setting it up to wait until after the particles are gone before you add the tnt because the carpet being placed on the ore will cause the ore to emit particles) Heres a screenshot:

(Obviously you don't need that much tnt)

Solution 2:

Let's start with an extremely simple case: A dark corridor that suddenly opens up a hole in the ground.

Here is the redstone, all black concrete was replaced with sandstone:

All pistons are sticky, the repeater is set to the second setting.

As requested, here is a clearer image of the redstone, all unnecessary blocks removed and the tunnel made out of glass (which would of course be a really bad idea in the actual trap):

The hole in the ground opens quickly enough that you fall through when walking over it regularly and even mostly when sprinting and closes late enough that the trapped player does not get suffocation damage from the piston (in case you don't want to kill the trapped player).

Materials:

• 2 tripwire hooks
• at least 4 string for minimum visibility, 3 possible
• 1 redstone torch
• 1 repeater
• 10 redstone
• 3 sticky pistons

Advantages:

• no damage to player, if you don't want to
• It's pretty much a guaranteed kill, if you want to (drop into lava or other kill mechanism). Even enderpearling out does not work, because the hole gets closed over the player.
• items can be picked up or destroyed
• reusable

Disadvantages:

• This only really works in narrow tunnels. The idea can be applied for bigger holes as well, but that is much more complicated.
• sometimes fails when sprinting and mostly fails when jumping in a higher tunnel
• holes in the side of the tunnel can only be hidden with dark blocks, otherwise lighting gives it away
• resource packs can make the trap very easily visible

Solution 3:

Liquid Update Detector is an extremely sensitive mechanism that is very easy to trigger with changes that are undetectable by a lot of other means - and can be concealed in floor, walls and ceilings through use of any waterloggable blocks - including any stairs, slabs and trapdoors. Anything providing a liquid update to the block in question will trigger it - adjacent door, trapdoor or fencegate being open/closed, breaking or placing a block, placing a flower in a flower pot, entering a piece of string/tripwire, using a bed, opening a barrel, and many more.

This is a design by Jing RS Lin, but you can find a couple others or devise your own - the concept is fairly simple; an observer watching water in 'illegal state' (obtained by failing to provide liquid update by a retracting piston head that retracts while failing to pull a slime block (because its attached blocks are blocked by an unmovable block or over push limit). In Jing's design, the slime block would try to move the glass and the observers, but can't because the furnace is in the way, so the piston head retracts - and so the water fails to flow into the created space; now any update to the waterlogged slab will make the water to flow and trigger the trap.

As for the trap itself, a modification of the simplest enderpearl station is another easy to trigger device (just provide a block update) and a barrage of 16 splash potions of damage II is hard to survive for anyone. The dispensers can be hidden behind trapdoors which will open automatically when the device activates. Alternatively, you can load up TNT. In this case the dispensers can be pointed directly into solid blocks (concealing them and protecting them from the blast) and as long as there's empty space underneath, they will just drop - you can put a dispenser on top of a ceiling, pointing down, and it will dispense the TNT through the ceiling. Although - this is slower and easier to escape.

Note these traps are very sensitive - meaning easy to trigger while building. Make sure to "arm" (load with potions/TNT) only once you've verified your 'finishing procedure' doesn't trigger the trap.