[Mutant Future] Chance to Know Languages

According to the core rules, characters with high INT scores have the means to learn additional languages at scores of 13, 16, 18, and 20. The following simple system of houserules is used to determine the chance a PC may already know a given language when it is encountered in the wastelands.

Xenophobia and ignorance is rife in the wastelands, with factionalism leading to many secret tongues. However, 'slots' for extra languages granted by high Intelligence can be left empty until the player wishes to try and use one - the character may simply happen to know the language spoken by those they encounter, if they wish to cash in a potential extra language.

To do so, make a Know Languages roll on a 1d6, and get a 6 or higher. A natural 1 is always a failure.

A character failing to know cannot roll again for that particular language unless they've spent significant down-time studying.

Languages of The Ancients (not counting machine languages) have a negative modifier, usually -1 but as much as -3 for obscure or heavily coded languages.

High Intelligence scores grant a bonus to Know Languages rolls.

16-17: +1
18: +2
19: +3
20: +4
21: +5

Further modifiers are based on the inverse of the Reaction Adjustment charts on pg 11 of the Mutant Future rulebook:

Mutant Human knowing language of:
MA -1
MP -2
PH -1

Mutant Animal knowing language of:
MH -1
MP -2
PH -2

Mutant Plant knowing language of:
MH -2
MA -1
PH -3

Pure Human knowing language of:
MH -1
MA -2
MP -2

Androids have a -2 reaction adjustment to all cases except machine languages, unless they have a background functionality in protocol, diplomacy, hospitality etc.  

Replicants can never 'already know' languages - their short lifespan makes it unlikely they will have learned a particular language encountered in the wild. They can still study and learn as usual though.

Machine languages should be treated on a case-by-case basis, with modifiers being applied for the level of technology used by the machine, its age, obscurity of functionality and so on. The language of vending machines should be far easier to know than that of nanites. 

NOTE: Generally, machine languages are not 'computer code', although there may be some slight overlap. I would keep any extra bonuses to Technology Rolls arising from knowing a machine language to a minimum - perhaps 5% if the Mutant Lord is feeling generous.