Can sequester be used to get nearly unlimited duration spell effects?

Question

As a follow-up to this answer, consider the following situation:

1. Be a wizard of a level high enough to cast sequester
2. Have a spellcaster friend that is willing to sacrifice himself "for the greater good" cast a beneficial concentration spell on you (for example, bless)
3. Sequester your friend while he is concentrating. This stops him in time, allowing the effects of bless to remain on you forever (or until something dispels either sequester or bless)
4. Repeat the above for different casters and spells and enjoy a plethora of concentration effects on yourself (and why not your party as well)

This method appears to be only limited by how many spellcasters you can convince to be willing to be sequestered (starting a school/order promising "eternal life" may help).

Apart from being a cheesy plan that a DM is unlikely to allow, would this actually work by RAW?

Answer 1

It depends on the nature of the concentration

The sequester spell says that the affected target "falls into a state of suspended animation", and that "time ceases to flow" for it. Basically you are frozen, you can't perceive your surroundings or take actions in this state.

The rules describe concentration as a conscious activity the caster performs. Apparently, if a caster is frozen in time, he/she can not do such an activity — can't think, can't perceive their surroundings, can't concentrate on something. But, strictly saying, is unclear if concentration would or would not work in this state — the rules are silent about this, making this a subject of a DM fiat.

Any reasoning would be valid:

• The target falls into a state of suspended animation, one second lasts forever for it, it goes into a frozen-in-time state, so it can not perform any conscious activity in real time, including maintaining concentration (a simulationist's approach)
• The Sequester spell details don't say the target is incapacitated, therefore, it can maintain concentration (a strict rules-as-written approach)

However, Bless still lasts 1 minute, no more

Unlike Time Stop, Sequester only stops time for one person. If this person cast the Bless spell, its effect still last no more than the spell duration is (1 minute in this case).

The last but not least. When a DM is making adjudications, they should think about players having fun, not the rules:

Always follow this golden rule when you DM for a group: Make decisions and adjudications that enhance the fun of the adventure when possible

If you find it ingenious enough for an evil NPC wizard in your campaign, just let him/her do that (by inventing a custom spell, I guess). If a PC wants the same, though — that probably could break your game (but this is another question).

Answer 2

This is going to be a DM's prerogative due to two related questions (partly asked here)

1) Is 'suspended animation' equivalent, rules-wise, to incapacitated?

2) Does 'stopped in time' also stop ongoing spells and effects originating from the suspended creature?

Since there isn't an official state of 'suspended animation' I can only go from the the English-meaning of the text. And for this I would say that suspended animation is pretty much the same as sleeping, which would certainly stop concentration.

In addition (but more dubiously) I would also say that 'time has stopped' would also suspend any ongoing spells and effects regardless of concentration.

None of this is RAW, because the rules doesn't really cover this unique state. As a killjoy DM I would probably rule against allowing this, but as stated its going to be a DM prerogative!

Answer 3

As a DM I would disallow a player from using this tactic. I think from a balance perspective, it would be game altering enough that it would create issues.

The game was built to generally only allow single concentration spells for one caster. And while there are a couple ways to break that, with things like storing a spell in a Shield Guardian (where the creature maintains the concentration after casting), Arcane Abeyance on the Chronurgy Wizard or Ring of Spell Storing where the activating character can maintain the spell (like a familiar), or storing spells in a Glyph of Warding (where the glyph is anchored in place and can't move). It's more difficult to do.

There's potential interaction with the Glyphs of Warding & Demiplane where you could create a bunch of Glyphs holding the spells in a single location, where you open that location, buff up, and now have a lot of concentration spells active at once. But that still limits the spells to their normal duration, takes a lot of preparation, and is expended once you do it without a lot more prepartion.

This would break all of those restrictions.

If you were to do this, consider the possibility of how it could combine with something like Simulacrum & Demiplane. You could create a Simulacrum. Have it use it's 7th level spell slot to cast another Simulacrum. Have it cast whatever buff you want that requires concentration. Sequester the Simulacrum. And then store that Simulacrum on a Demiplane. Rinse & repeat until you have all the buffs you want. The multi-simulacrum tactic itself is already one that I think most DMs would frown upon. But if you are going to allow never ending multiple concentration buffs, you're already beyond that in terms of broken mechanics.

This tactic wouldn't require the sacrifice of a player character for it. A singular Wizard could do it by themselves. That's not really going to end well for a DM trying to run a balanced game.

There would be ways to deal with it. Dispel Magic could take care of it. And there are other ways to end spell effects. But then you are getting into a constant game of cat & mouse between you and that player.

Could it work? Depends on the nature of concentration. But I would recommend against it.