How can I manage my player's perpetual invisibility?

Question

I'm mastering a game using the MERP second edition rules. One of the players was lucky enough to start with an Item which contains a daily spell, which he chose to be Invisibility (from the Illusion path) which is a level 4 spell. As the rulebook states, if the spell chosen is of level 4 it can be used once a day.

4 - INVISIBILITY (E) As Unseen, except everything within 30cm of the target is invisible as long as it starts and remains within the 30cm radius.

Unseen in turn says:

2 - UNSEEN (E) A single object (or being) is made invisible (1 garment, 1 naked body, etc.) until 24 hours pass OR the object is struck by a violent blow (being hit by a weapon, falling, etc.) OR the object (or being) makes an attack.

The spell grants the user invisibility for 24 hours, which is a whole day. The player is trying to abuse the system by not leaving his invisibility state and reactivating it right after 24 hours, not stopping from being invisible ever. He waits for the spell effect to finish before executing his move, in order to become invisible again without spending too much time being visible.

(The other players are fine having an invisible, one-action-a-day companion. As long as he helps with acomplishing their goal, they don't really care about not seeing him. In addition he's sharing his earnings so everyone's happy. Of course he has not been invisible for the whole campaign, just whenever they enter a new location, when he starts his stealing rampage while the rest act as normal people gathering information and so on. He'll leave his perma-invisibility when facing bigger dangers and the rest of the team needs help, but he'll usually wait for entering combat.)

As it's just too powerful because it's not using any of his power points I tried to limit it by making the cooldown of the item start when the effect stops, but the player claims that the item, just as a human caster, does not need to keep casting the spell to become invisible, so the cooldown for the item should start counting since it was cast.

He is right in his statement and I can't disagree with him, so he's free to rob/steal or even kill if waiting for the 24 hours of the spell coming to an end before striking his blow to the objective to then become invisible again.

Is there a rule which restrict this kind of abuse or did he made a really nice strategy to advance through the game?

Answer 1

Thievery

Part of your answer is in the quoted text...

as long as it starts and remains within the 30cm radius.

Unlike other games' invisibility, this effect doesn't apply to things the character picks up after the spell goes into effect - they explicitly have to be on him (or within 30cm) when he casts the spell. Anything the character attempts to steal will remain visible.

A related, and somewhat disgusting, stumbling block is what happens when he eats. If he tries to spend his whole life invisible, he'll have to carry food with him when he triggers his invisibility. What visible, eaten food looks like inside an invisible person is an image I'll leave to others imaginations.

Murder

Another factor is the unreliability of pre-modern timepieces. The idea of him killing somebody and then immediately becoming invisible again requires precise timing. He needs to strike the blow (and kill with the first blow) exactly 24-hours after becoming invisible. Even if he can time it so precisely, there's still a narrow window between becoming visible and being able to trigger the invisibility again.

Of course, even if he somehow did have an exceptionally precise portable timepiece, everything he's carrying becomes invisible when he casts the spell. He may not be able to see a watch, even if he has one.

Summary

In response to your final question, though not an answer to the specific wording... Your player is very much trying to abuse the system. He's not really being all that clever about it, though.

Answer 2

It strikes me that for the GM in this case timing is everything. If you force the character into interactions for which they have to be visible, such as being hired, or recognised (read paid) for services shortly after they renew their invisibility it will make life awkward for them. Have the spell wear off during an encounter, preferably without the character immediately noticing, because they've lost track of time in all the excitment.

The other option is to exploit the

"OR the object is struck by a violent blow"

deactivation clause in Unseen; Invisible people should regularly get hit, stood on, and/or tripped over because people can't see them. My favourite example that points this out being the Je Souhaite episode of the X-Files where an invisible man gets hit by a truck as a direct result of his invisibility. To apply this to your situation; trying to move through a crowd should be a bad experience for an invisible character, they should get barged into and tripped over by more than one NPC. Getting into busy rooms without ending up visible, either jammed in or knocked down by a closing door, or exiting customer, a major feat of skill and agility. Have the character distracted crossing the road and sideswiped by a wagon, little to no damage done but the spell gets cancelled, if what distracted him is the victim of his latest theft and they see it happen... you get the idea.

Answer 3

He can only use the power once per day. As is, it's fine. They get one powerful ambush from the shadows and just one, and only if they do it during a short duration of time which counts as 24 hours. If you want to test them, attack them with more than one enemy or more than one thieving job and make them choose what to use invisibility on.

As TJ noted, there are some serious complications in their plans, but being quite effective for a single action is not that overpowered.

You noted that your issue was them doing immoral acts without consequence. If you want the group to have a ban on immoral acts, it's worth talking to them about it. One player shouldn't be singled out, especially if everyone is having fun. If you want them to face dramatic consequences then it would be better to escalate things. Have them spy things too large to smuggle out on their person, but valuable, and have the merchants band together to hire mercenaries or trouble shooters to handle them, or to take the ring.

Answer 4

I only find this now. After so many years. Hahaha. I also had a group of players with a mage and once he reached lvl 5 he made them all flying and invisible a soon as things got a little hairy.

I solved it by defining that an invisible person would be slipping into another plane of existence: the "ghost world". This is the same plane that Frodo enters when he puts on the one ring. Like in the movies the invisible persons perception of the real world is severely impacted. He can only see shadows and silhouettes of the real world and navigating and movement becomes a pain with constant orientation checks. Melee attacks are still possible but using ranged weapons is not.

My players hated me at first but this change brought back a lot of challenge and ultimately fun.