It could be argued that TNE or T4 is NOT the same usniverse as CT/MT, as the primary N-space drives don't work the same way...
And the rules differences make huges setting differences.
In CT/MT/T20, you can expect a ship to be able to routinely make 1.99 jumps per month.
In TNE, you can't assume that; in fact, due to far less delta-v available, you can often find 1.2 jumps per moth difficult.
T4 is yet again another paradigm; those clunky delta-v restricted HEPlaRs are still there, but TPlates come back.
In TNE, CT, MT, T4 and T20, the effects of a hit by a Gauss Rifle vary a good bit. TNE, MT, T4, and T20 all reduce damage for worn armor. CT makes it harder to be hit, rather than reducing damage, for worn armor. Likewise, a hit under CT does base damage. Under MT, damage varies by quality of hit, from negligible (x1/2 for hit roll quality) to lethal (x8). Under TNE, damage is not routinely affected by quality of hit; double damage on crits is there. T4, I don't recall modifications to damage by hit quality, only for armor, but I'm too #!&^## lazy to look it up. T20 has a critical for a damage multiplier by weapon, and has some effects of damage reduced by armor except on crits; in T20 a young kid goes out well before death; SgtMaj Grizzly, 30 year vet, however, will die before passing out if unarmored, and may die before passing out even if armored.
A ruleset is a set of definitions for how the universe operates; certain thigns are consistant for the setting across rulesets:
There is a big empire called the 3rd imperium, founded by a man named Cleon. It has nobles, a big navy, big ships in the navy, a marine corps, a scout service, psionic enemies called the Zhodani, paranoid enemies called the Solomani, Technophile Starfish-like aliens called Hivers as sometimes allies, sometimmes not, 2D Jumpspace, jumps take around 7 days, the year is 365 days even, 1G=10m/s^2, C=300Mm/s, firearms are still viable, and gravitic lift vehicles (even if that grav lift is actually only 99% of weight in TNE); all seem to have really extremely long range lasers.
Lots of details vary widely:
JFuel: CT, T4, T20, GT: 10% of hull per Jn per jump of Jn Pc.
MT and TNE: 5*(Jn+1)% of hull per Jump of Jn Pc
TPlates: Explicit in MT, T4
Explicitly NOT in Canon TNE
can be inferred from CT, but not explicitly there
GT: Don't recall
T20: implied but, IIRC, not explicit in T20.
Gravitically Focussed Lasers:
CT, MT, T20: can be inferred from the ranges to exist
TNE,T4:explicitly there to get the ranges listed in CT.
GT: Don't know
Cybernetics:
CT: not mentioned in core materials
MT: mentioned in passing, no rules in core
TNE: rules in core (specifically, FF&S) for numerous cyber items
T4: similar to TNE. Don't recall if any are in T4 core book
T20: in core book
GT: not in core book, but references to other GURPS products wich have them are.
And the rules differences make huges setting differences.
In CT/MT/T20, you can expect a ship to be able to routinely make 1.99 jumps per month.
In TNE, you can't assume that; in fact, due to far less delta-v available, you can often find 1.2 jumps per moth difficult.
T4 is yet again another paradigm; those clunky delta-v restricted HEPlaRs are still there, but TPlates come back.
In TNE, CT, MT, T4 and T20, the effects of a hit by a Gauss Rifle vary a good bit. TNE, MT, T4, and T20 all reduce damage for worn armor. CT makes it harder to be hit, rather than reducing damage, for worn armor. Likewise, a hit under CT does base damage. Under MT, damage varies by quality of hit, from negligible (x1/2 for hit roll quality) to lethal (x8). Under TNE, damage is not routinely affected by quality of hit; double damage on crits is there. T4, I don't recall modifications to damage by hit quality, only for armor, but I'm too #!&^## lazy to look it up. T20 has a critical for a damage multiplier by weapon, and has some effects of damage reduced by armor except on crits; in T20 a young kid goes out well before death; SgtMaj Grizzly, 30 year vet, however, will die before passing out if unarmored, and may die before passing out even if armored.
A ruleset is a set of definitions for how the universe operates; certain thigns are consistant for the setting across rulesets:
There is a big empire called the 3rd imperium, founded by a man named Cleon. It has nobles, a big navy, big ships in the navy, a marine corps, a scout service, psionic enemies called the Zhodani, paranoid enemies called the Solomani, Technophile Starfish-like aliens called Hivers as sometimes allies, sometimmes not, 2D Jumpspace, jumps take around 7 days, the year is 365 days even, 1G=10m/s^2, C=300Mm/s, firearms are still viable, and gravitic lift vehicles (even if that grav lift is actually only 99% of weight in TNE); all seem to have really extremely long range lasers.
Lots of details vary widely:
JFuel: CT, T4, T20, GT: 10% of hull per Jn per jump of Jn Pc.
MT and TNE: 5*(Jn+1)% of hull per Jump of Jn Pc
TPlates: Explicit in MT, T4
Explicitly NOT in Canon TNE
can be inferred from CT, but not explicitly there
GT: Don't recall
T20: implied but, IIRC, not explicit in T20.
Gravitically Focussed Lasers:
CT, MT, T20: can be inferred from the ranges to exist
TNE,T4:explicitly there to get the ranges listed in CT.
GT: Don't know
Cybernetics:
CT: not mentioned in core materials
MT: mentioned in passing, no rules in core
TNE: rules in core (specifically, FF&S) for numerous cyber items
T4: similar to TNE. Don't recall if any are in T4 core book
T20: in core book
GT: not in core book, but references to other GURPS products wich have them are.