Sums of 100 Rolls of Two Six Sided Dice
Jelly, 13 12 bytes

³Ḥ6ẋX€+2/ṢŒr


A niladic link. Output format is a list of lists of [value, count].

(Zero rolls means no such entry is present in the output - e.g. an output of[[6, 12], [7, 74], [8, 14]] would identify that only sums of six, seven and eight were rolled.)

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How?

³Ḥ6ẋX€+2/ṢŒr - Main link: no arguments
³            - 100
 Ḥ           - double = 200
  6          - 6
   ẋ         - repeat -&gt; [6,6,6...,6], length 200
    X€       - random integer from [1,z] for €ach (where z=6 every time)
       2/    - pairwise reduce with:
      +      -   addition (i.e. add up each two)
         Ṣ   - sort
          Œr - run-length encode (list of [value, length] for each run of equal values)