Can a tenant ever terminate their legal obligations of a lease during its term?
Yes, there are three ways a tenant's legal obligations can be terminated:
(1) legal misconduct of the landlord;
(2) replacement in the premises by a new tenant, or
(3) agreement between the landlord and tenant.
If the landlord does not maintain the premises, this may constitute legal misconduct. Local laws may provide for lease termination if there are undisclosed code violations or there are problems accessing the premises by the tenant.
If another tenant has moved in and is paying the full amount of rent, the first tenant's obligation is ended. A landlord cannot legally collect rent from more than one tenant for the same premises.
The landlord and tenant can always end their lease obligations by mutual agreement.