Most ramming even in the star trek universe only happened (or was planned)because they wanted to stop an enemy fleet ship from getting to a home planet (borg and earth for example) or the fact the crew were clones programmed to to as they were told and nothing else.
Reality is in the normal star trek and not TNG, this did not happen often due to the hundreds of crew aboard, they would only do it out of desperation and even then if they thought they could not get away alive.
So if they did make these valid rules it would have to have the following draft rules:-
A)The ship would have to be crippled
B)The Ship would have to take a command check to do it, if failed it cannot do anything this turn (as the crew have phasered the captain or something)
C)the ship can only move in a straight line and must use the "all power to engines" order
D)They cannot fire any weapons that turn.
E) when it does ram it and its target ship will have to make an opposed command check with the target to see if they hit
F) if they miss they must move their full movement from the Start of thier movement position
G) both ships take half hull hits of the opposite ship starting hull it i.e. a Constitution ramming a D5, the constitution would suffer 9 hits and the D5 would suffer 16 hitsAs you can see a long list and a small chance of hitting anything with a 25% chance of a actual hit.
Let me know what you think
"Target that ship, fully impulse!"