Does an item change the game balance in the same way with different PC classes?

Question

I am running a custom campaign as DM with two players, P1 and P2. P1 plays as a Druid while P2 plays as a Warlock/Rogue whose game style is based on being stealthy. I let P1 find a Staff of the woodlands which, among the varius properties, lets the character cast Pass without trace (+10 to Stealth checks) without using slots or charges.

P2 asked me to let him find a similar item, since he often needs Stealth checks. At the beginning I pleased him with an item with the same effect, but then I realized that it needed some limitations, since P2 already has +11 to Stealth and therefore (almost?) every check would result in a success with the new item.

I stated that I wanted to introduce some limitations for the next game session, but P2 complained saying that this is unfair, since P1 has the same item (with additional properties). Also, I could not change the properties of an item that I had already introduced. I replied that P1 doesn't have +11 Stealth (and he never will) and his game style doesn't include a lot of Stealth checks, so the problem does not exist for him.

Now, after this long introduction the question is: is my reasoning correct? I tried to consider the characters skills and I realized that the game was going to be unbalanced. I am a novice DM so please tell me if I should behave differently.

Answer 1

Yes items can become balance breaking in combination with classes and/or feats. Your observations are correct.

You could always reduce the bonus your P2 gets to a level that is reasonable. You could explain this, for example, by saying that the magic of the item does work normally but as a professional in stealth, his character would not leave much of a trace for the magic to remove in the first place. So it does not help him as much as it would a novice in stealth.

When handing out items always tell your players that the effect is temporary for now and you might change it later if it is causing problems. Your main error was handing out the item without telling P2 that you will have to change it if it is causing problems.

You should try talking to P2. It is obvious what the problem is. To still challenge his character you would have to set DC for stealth checks to 30 or something. This would result all other member of the party instant failing these checks. (As they might only have an amazing +10.)

This is no fun for the rest of the group.

Answer 2

I think this is a case of "fun trumps rules". If the staff is causing issues that make the game unfun, it needs to be nerfed or removed. I would ask P2 to think of a reasonable alternative that he would find fun. Because taking cool stuff away is also unfun.

On the other hand, if the staff isn't really causing issues, taking the staff away could actually be unfair. Maybe you can just raise DCs on stealth checks a bit as you introduce new, more powerful enemies. Then P2 can mostly auto-sneak around the peasant rabble, but the enemy's newly-trained spotters will make sneak-attacking the big bad almost impossible.

Because bonuses are additive, giving both players a +10 stealth, then raising all stealth DCs by 10, will end up with both players at the same equal place they started. Raising DCs by 5 would effectively cut the bonuses in half without negating the benefit of the staves. This is still a cheap DM tactic, so don't do it constantly. But it could work better for the players than taking stuff from them.

Answer 3

Play balance is the constant bugbear of game mastering. I try to let my players know if there's a problem, but it's always hard to take away a shiny thing you've given them.

In your specific case, 5e has a very good mechanic to apply. If you want to retroactively change the item so that the character with the lower skill gets a significant boost, yet the higher skilled player is not made invincible, use Advantage. Instead of giving a flat +10 (which is awesome in the era of bounded accuracy) let it grant Advantage to Stealth checks.

The character with the bonus that places him nearer the center of the success curve automatically benefits more than the player near the top, yet the mechanic is identical.