In our two-week old campaign, the DM is trying to say I need food or water, or otherwise I'll suffer from exhaustion.
But I am a Warforged Juggernaut, and the Warforged Resilience trait says I don't eat, sleep, breathe, etc. (WGtE, p. 68):
- You don’t need to eat, drink, or breathe.
- You don’t need to sleep and don’t suffer the effects of exhaustion due to lack of rest, and magic can’t put you to sleep.
Can the DM override my racial traits?
He feels my race is too overpowered and he wanted to even it out. He claimed the only way for me to die is to be "crushed by a tarrasque".
He offered to give me immunity to one element to compensate for the ability to gain exhaustion. I picked immunity to undead because that's his entire campaign.
Best Answer
The Direct Answer
The direct answer is yes, the DM can override racial traits and absolutely anything else they want to override.
Your Specific Situation
This would be an odd thing to override. First, most campaigns don't make a big issue out of food and water. They are often assumed to be adequately available so that it doesn't become much of a mechanical issue. They are often mentioned in story and fluff, but rarely an issue (not never, I've seen it raised in survival situations with low level characters in earlier editions).
Also, that is a legitimate advantage of warforged provided as part of its racial balance. In campaigns where the availability of food and drink is an actual issue, the fact warforged don't need to worry about that problem is an advantage of the race written into the standard rules.
How to handle it
As is often the answer, you should talk to your GM. Its likely they forgot about that trait.
It is also possible they are doing it deliberately. While rare in my experience, some gritty campaigns do make food and water an issue, especially in harsh areas where the availability is low and acquiring the necessary supplies can be a challenge meant to be solved in game. If the GM is making a deliberate point of it in the campaign, they may not want your character to be simply immune to it.
However, if they are doing it deliberately, they are depriving your character of a legitimate advantage and doing it in a way that doesn't fit well storywise with the warforged. You may want to work with them to have them give you some other minor trait to compensate and to provide a story explanation for why your warforged needs it that fits well.