As far as I'm aware, there is no way to maintain concentration on two effects at once. There are plenty of ways to get advantage on or reroll a failed save to maintain concentration on an effect, but there isn't a feature or item that allows for concentration on more than one.
Concentration exists as a balancing feature. It keeps spellcasters in check and forces them to consider their options carefully, as well as hang back to avoid breaking concentration. If it were possible for a character to maintain concentration on multiple effects at once, or if concentration wasn't necessary at all, then it would be far too easy for spellcasters to wreck the battlefield by stacking powerful spells.
You can home-brew something if you'd like, just know it may break your game.
Some items emulate effects similar to specific spells that require concentration. In that way, you can sorta have multiple effects active at the same time, if you were to achieve the same thing with just using spells.
But in general, no, I don't believe that there is anything like that possible. It's a balance thing, and core to the game that one concentration only is allowed.
Previous threads on this topic have highlighted things like the sorcerer’s Twin Spell metamagic and using items like a ring of spell storing with a familiar or party member. Depending on what you are trying to do, those might help, but otherwise the others have correctly pointed out the lack of a way to flexibly and frequently bypass the restriction on concentration.
You can use a glyph of warding to achieve that for some spells. You can for example have the glyph cast fly on you and it will concentrate on that spell for you, leaving you to cast another concentration spell.
However, the limitations on the glyph make that impractical for adventuring.
The easiest way RAW is to get a Ring of Spell Storing and have a non-spell caster or familiar wear it and stock it with spells that require concentration. Then they can cast the spell from the ring and concentrate on it.
Is there a ways to do it with or without a magic item?
As far as I'm aware, there is no way to maintain concentration on two effects at once. There are plenty of ways to get advantage on or reroll a failed save to maintain concentration on an effect, but there isn't a feature or item that allows for concentration on more than one.
Concentration exists as a balancing feature. It keeps spellcasters in check and forces them to consider their options carefully, as well as hang back to avoid breaking concentration. If it were possible for a character to maintain concentration on multiple effects at once, or if concentration wasn't necessary at all, then it would be far too easy for spellcasters to wreck the battlefield by stacking powerful spells.
You can home-brew something if you'd like, just know it may break your game.
Some items emulate effects similar to specific spells that require concentration. In that way, you can sorta have multiple effects active at the same time, if you were to achieve the same thing with just using spells.
But in general, no, I don't believe that there is anything like that possible. It's a balance thing, and core to the game that one concentration only is allowed.
Altrazin Aghanes - Wizard/Fighter
Varpulis Windhowl - Fighter
Skolson Demjon - Cleric/Fighter
Previous threads on this topic have highlighted things like the sorcerer’s Twin Spell metamagic and using items like a ring of spell storing with a familiar or party member. Depending on what you are trying to do, those might help, but otherwise the others have correctly pointed out the lack of a way to flexibly and frequently bypass the restriction on concentration.
You can use a glyph of warding to achieve that for some spells. You can for example have the glyph cast fly on you and it will concentrate on that spell for you, leaving you to cast another concentration spell.
However, the limitations on the glyph make that impractical for adventuring.
More Interesting Lock Picking Rules
The easiest way RAW is to get a Ring of Spell Storing and have a non-spell caster or familiar wear it and stock it with spells that require concentration. Then they can cast the spell from the ring and concentrate on it.
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