# What happens when you try to install a hunting trap on the square of a creature?

If you move to a square adjacent to an enemy creature then attempt to install a hunting trap on the creature's square, what would happen ?

1) you can't do that, as the square is occupied and therefore unavailable for your sneaky little hands to install the trap on it

2) you can install the trap, and if the creature later moves out of its square (provided that it does not float, fly, jump or teleport away), it will activate the trap and have to make the DC

3) you can install the trap, but it won't affect the creature if it then moves out of its square (only if it moves on the square again later on)

4) other scenario I didn't think of

• It "roots" them of course. Not sure what the square root of a creature is though. Bad math joke, sorry. Commented Mar 14, 2018 at 16:31
• Hehehehehehehehe Commented Mar 14, 2018 at 16:32
• @Slagmoth Some of my Australian friends will have a good laugh at your comment. Commented Mar 14, 2018 at 20:00

# You set the trap and it will trigger if the plate gets stepped on

Nothing says the space where you set the trap needs to be unoccupied.

When you use your action to set it, this trap forms a saw-toothed steel ring that snaps shut when a creature steps on a pressure plate in the center.

However, it also doesn't say that entering the 5 foot area the trap is within or being within the 5 foot area activates the trap necessarily.

A creature that steps on the plate must succeed on a DC 13 Dexterity saving throw or take 1d4 piercing damage and stop moving.

(emphasis mine). As such, number 3 is the closest to the correct answer if and only if the creature steps on the pressure plate when "it moves on the square later on." If the creature is smart enough to avoid the pressure plate in the center then it won't activate.

• If being in the same space doesn't activate the trap, then what are the mechanics to determine activation? It seems like location (the space) and the Dex Save are doing that. Commented Mar 14, 2018 at 17:20
• @NautArch Stepping on the pressure plate is an entirely seperate activity then entering the space. As a DM I would rule that most unintelligent creature (3 int or less) would not identify the trap as a threat and would step on the plate most of the time within that square. Any creature that is slightly higher (4 or 5) might step on the plate (or mess with it) on purpose to see what it is or avoid it altogether. Anything above that would recognize the spikes as a threat and avoid and 8+ is person intelligence, smart enough to enter the square without touching the plate (unless moved forceably) Commented Mar 14, 2018 at 17:23
• Interesting, so the DC check isn't automatic - you first have created a system to determine if there needs to be a DC check at all. Commented Mar 14, 2018 at 17:24
• @NautArch That's how I would do it. RAW there is no ruling on when or whether a creature steps on the plate. Commented Mar 14, 2018 at 17:26

# You are able to place the trap, and if the creature steps on it they will be subjected to it's effects.

Most traps have triggers, and this one is explicitly specified, and that trigger is "A creature that steps on the plate."

The description of the hunting trap, in the PHB under adventuring gear, doesn't specify a creature's space or the square they're standing on. The description only states if they step on it. Assuming he saw you plant the trap, they wouldn't step in it, willingly, unless they were unintelligent. But maybe they could be pushed onto it, or another creature could step on it later.

A DM might rule that being on the same square counts as "stepping on the trap," but, I would rule that you can't place a trap under a conscious target, without triggering it yourself.

I would rule this like the following:

1. You place the trap, using your action
2. The DM decides whether or not your trap is hidden. This can be determined by deciding if you were seen setting the trap. If you were seen setting this trap, the trap isn't hidden. If the battle is hectic, he might rule that the trap is hidden.
3. The DM then sets a DC to notice the trap, and checks that against the creature's passive perception score.
4. If the creature doesn't notice the trap, and then moves (because you can't place it directly underneath the creature), the DM will determine whether the creature stepped on that trap or not, and then consult the trap description if the creature stepped on it.
• Is that how you'd rule (if so, why), or do you have written rules/clarifications to support this answer? Commented Mar 14, 2018 at 17:57
• @nautArch The ruling comes from the description of the hunting trap item from the PHB. It's located under adventuring gear. Commented Mar 14, 2018 at 18:07
• That description doesn't cover not stepping in it willingly. Only that if the plate is stepped on, then the creature must make a Dex save. There is nothing in there suggesting opting NOT to step on the hunting trap - nor is there anything about how/where you can place it. ANd personal rulings are fine here, but you should generally try and support it by either existing rules or examples of use in gameplay. Commented Mar 14, 2018 at 18:22
• @nautarch You're making some strange assumptions. Given the option that you can step on it automatically implies that you can choose to not step on it. A trap has a trigger, and when noticed (via passive perception) you can choose to disarm it, or trigger it. The trigger is "step on the trap". Commented Mar 14, 2018 at 18:30
• Even though it has trap in it's name, I didn't think to use trap mechanical for it. It may help your answer to include the sequence of how you see it all coming together (include dm setting the DC to perceive the trap...which should be pretty low because they saw it set...but maybe they we're distracted by the combat.) Commented Mar 14, 2018 at 19:38