It's a role-play. If a die roll was performed to decide about what your character would do, than it makes no sense and denies nature of game. Any action taken by your character should be dictated by playing a role (with minor exceptions).

However dice rolls may be used to check outcome of these actions, as in kviiri's examples.

So to answer your question: DM is allowed to perform such rolls, but your DM used it wrong way. Though it desn't mean that outcome would be different if checkes would be used properly.

To me such situation should be played like this:

• CH1: <tries to deceive your character (CH2)>
• DM: Both roll - CH1 for deception, CH2 saving throw for wisdom
• [It seems that your saving throw was lower than CH1 deception throw]
• CH2: <Believes in lie and acts accordingly>

The last line probably means same output as your DM forced you to do, but not necessarily. It's up to you really, though it seems like most probable and realistic behavior.

D&D is role-play. If a die roll was performed to decide what your character would do, then it makes no sense and denies the nature of the game. Any action taken by your character should be dictated by playing a role (with minor exceptions).

However, dice rolls may be used to check the outcome of these actions, as in kviiri's examples.

So to answer your question: The DM is allowed to perform such rolls, but your DM used it the wrong way. Though it doesn't mean that the outcome would be different if the checks were used properly.

To me, such a situation should be played like this:

• CH1: <tries to deceive your character (CH2)>
• DM: Both roll - CH1 for a Deception check, CH2 for a Wisdom saving throw
• [It seems that your saving throw roll was lower than CH1's Deception check]
• CH2: <Believes the lie and acts accordingly>

The last line probably results in the same outcome as your DM forced you to do, but not necessarily. It's up to you really, though it seems like the most probable and realistic behavior.