Grognard's Grimoire: Stranger

Given the prominence given to Barsoom in the LBBs and how much of Appendix N is taken up by books in which 20th century Earthmen find themselves transported to fantasy worlds, it's amazing to me that it's never been formally included into any edition of Dungeons & Dragons.

Here's my initial pass at a Labyrinth Lord-style character class based on this premise. The entirety of this class is hereby designated as Open Game Content via the Open Game License.

Stranger

Requirements: CON 9
Prime Requisite: CHA
Hit Dice: 1d8
Maximum Level: None

As their name implies, Strangers are human beings from another world/time/dimension, who are trying to make a life for themselves as best they can in their new homes. Despite their otherworldly origins, Strangers possess preternatural adaptability, being able to learn local customs and languages with surprising ease. Consequently, Strangers may learn the local equivalent of Common within hours of first hearing it, regardless of their INT score. Similarly, they suffer no reaction penalties when dealing with alien species/cultures. Indeed, many Strangers find themselves looked upon as long-sought heroes and liberators, whose mysterious arrival portends revolutionary changes in the status quo. Unsurprisingly, Strangers find allies and enemies in equal number.

Perhaps because journeys between worlds/times/dimensions are inherently hazardous, only the most resilient -- and fortunate -- Strangers survive. Members of this class use the same saving throw charts as Fighters but gain a +4 bonus. Owing to the unusual nature of their fighting styles, Strangers gain a +1 bonus either to Armor Class or to hit and damage when fighting opponents unfamiliar with their ways. Which bonus the Stranger wishes to use must be declared before each combat begins and, should the opponent survive to face the character again, the bonus is nullified thereafter in the case of that particular foe.

Stranger Level Progression
Experience	Level	Hit Dice (1d8)
0	1	1
2,187	2	2
4,375	3	3
8,751	4	4
17,501	5	5
35,001	6	6
70,001	7	7
140,001	8	8
280,001	9	9
400,001	10	+2 hp only*
540,001	11	+4 hp only*
660,001	12	+6 hp only*
800,001	13	+8 hp only*
1,000,001	14	+10 hp only*
1,200,001	15	+12 hp only*
1,400,001	16	+14 hp only*
1,600,001	17	+16 hp only*
1,800,001	18	+18 hp only*
2,000,001	19	+20 hp only*
2,200,001	20	+22 hp only*

*Hit point modifiers from Constitution are ignored.