Please add numeric-conversion capability to the search mechanism. Tons of games have sequels that are either written as VII or 7. Case in point: I posted this because I didn't see this when I was typing the question and leafing through the related questions. Can patterns that match roman numerals be translated to numerals and added to the search? It might be a little rarer, but numbers could be translated as well and added to the search, so that FF7 matches posts for FFVII.
A solution would be to extensively use the tag synonyms for the games that use roman numerals and do not have a game known under the normal numerals.
The tags page allows character-by-character incremental search. It should cover all your prefixation needs.
The point was made that some Megaman games are numbered 1, 2, 3 and some are numbered I, II, III. (reference)
And what happens if/when we get a medical SE and somebody performs a search for IV (intravenous) catheters? They'll get a bunch of unrelated questions that happen to have a '4' in their bodies.