... I don't really get this whole "deadly as Traveller Rules as written" meme that people keep saying:
A Traveller Character has between 6 (222222) and 45 (FFFFFF) "hit points" with an average of 21 (777777).
A first level Basic D&D Character (same era game) has between 4 HP (Magic user no Constitution bonus) and 12 HP (Fighter with maximum Constitution) with an average of 8 HP (D6+2 Con) [1 HP minimum and 5.5 HP average of you actually roll per R.A.W.].
A Traveller rifle/shotgun will do 3D6/4D6 per attack delivering 10.5/14 average and 18/24 maximum damage per attack to characters with an average of 21 "HP".
A D&D Bow/Longsword will do 1D6/1D8 per attack delivering 3.5/4.5 average and 6/8 maximum damage per attack to characters with an average of 5.5 "HP".
The maximum long range attack in Traveller (3D6 rifle) will not kill the average Traveller character with a single shot even at maximum damage (18 damage vs 21 "HP") while the maximum long range attack in D&D (1D6 bow) will kill the average D&D character with a single shot at maximum damage (6 damage vs 5.5 "HP"). For both games, the average damage requires two hits to kill the average character.
For close range combat (shotguns and swords), the average character will survive average damage from a shotgun blast in Traveller (14 dam/21 hp) and the average character will survive the average longword attack in D&D (4.5 dam/5.5 hp). Maximum damage will kill the average character in both systems (24 dam/21 hp & 8 dam/5.5 hp) and maximum damage will not kill maximum HP in both systems (24 dam/36-45 hp & 8 dam/12 hp).
So D&D is deadlier for characters than Traveller ... but everyone doesn't choose other combat systems and complain about how "deadly" combat is in D&D.
A Traveller Character has between 6 (222222) and 45 (FFFFFF) "hit points" with an average of 21 (777777).
A first level Basic D&D Character (same era game) has between 4 HP (Magic user no Constitution bonus) and 12 HP (Fighter with maximum Constitution) with an average of 8 HP (D6+2 Con) [1 HP minimum and 5.5 HP average of you actually roll per R.A.W.].
A Traveller rifle/shotgun will do 3D6/4D6 per attack delivering 10.5/14 average and 18/24 maximum damage per attack to characters with an average of 21 "HP".
A D&D Bow/Longsword will do 1D6/1D8 per attack delivering 3.5/4.5 average and 6/8 maximum damage per attack to characters with an average of 5.5 "HP".
The maximum long range attack in Traveller (3D6 rifle) will not kill the average Traveller character with a single shot even at maximum damage (18 damage vs 21 "HP") while the maximum long range attack in D&D (1D6 bow) will kill the average D&D character with a single shot at maximum damage (6 damage vs 5.5 "HP"). For both games, the average damage requires two hits to kill the average character.
For close range combat (shotguns and swords), the average character will survive average damage from a shotgun blast in Traveller (14 dam/21 hp) and the average character will survive the average longword attack in D&D (4.5 dam/5.5 hp). Maximum damage will kill the average character in both systems (24 dam/21 hp & 8 dam/5.5 hp) and maximum damage will not kill maximum HP in both systems (24 dam/36-45 hp & 8 dam/12 hp).
So D&D is deadlier for characters than Traveller ... but everyone doesn't choose other combat systems and complain about how "deadly" combat is in D&D.