Sure! Here is a test case generator for the "Deadly Dice Game" problem:

```python
import random

def tcgen():
    # Randomly generating values for N and T within their given constraints
    N = random.randint(1, 2000)
    T = random.randint(1, 2000)
    
    # Generating a random string of 'R' and 'B' of length N
    cells = ''.join(random.choice(['R', 'B']) for _ in range(N))
    
    return N, T, cells

def main():
    # Generate a number of test cases, for example, 5
    num_test_cases = 5

    for _ in range(num_test_cases):
        N, T, cells = tcgen()
        print(f"{N} {T}")
        print(cells)
    
    # End of input
    print("0 0")

if __name__ == "__main__":
    main()
```

### Explanation:
1. **N and T Randomization:**
   - `N` and `T` are randomly selected between 1 and 2000.

2. **Cells Generation:**
   - The string `cells` is generated randomly, consisting of characters 'R' and 'B' with a length of `N`.

3. **Test Case Format:**
   - Each test case starts with a line containing `N` and `T`.
   - The next line contains the string of cell colors.

4. **Terminating Input:**
   - After generating the required number of test cases, the generator prints `0 0` to indicate the end of input.

This generator produces random valid test cases for the given problem and should help you test your solution comprehensively.