I've been researching some stuff about a certain game's probability systems and there are many cases when.... I can't really put it into words, so here's an example:
15% + 60% = 75%
15% is the base percentage, and it is often called so in the description text. The 60% in its own context is also called a percentage (but never with the base word). And the formula for the total chance is:
Resulting Percentage = (Base + X) * Multiplier
Without X being explicitly called anything comprehensible.
What should the X thing be called?