1870: Railroading Across the Trans Mississippi from 1870

1. Setting and huge map
1830 covers the northeastern United States with a relatively compact map. 1870 takes place west of the Mississippi, with a very large map designed so that most (if not all) companies that manage to float can end up being profitable, instead of the more competitive, resource-constrained scenario of 1830.

2. Ten public companies and six privates
1870 has a total of ten public companies and six private companies, a different ratio and game scale from 1830, with more room for parallel expansion without constantly clashing with rivals.

3. Share price protection
A mechanic that doesn't exist in 1830: 1870 includes "price protection" rules that cushion a company's market value from dropping under certain circumstances, making stock management somewhat less harsh than in 1830.

4. Share redemption to get back under the certificate limit
In 1830, a player who exceeds the certificate limit simply cannot buy more. In 1870 there is a share redemption mechanism that lets you get rid of shares to fall back within the allowed limit, a release valve that 1830 doesn't offer.

5. Share reissue at a 25% discount
When a company reissues its own treasury shares in 1870, it can do so at a 25% discount off the current market price. In 1830, issuing new shares (when possible) is always done at market price, with no such built-in discount.

6. Destination bonuses
1870 rewards companies that connect to their assigned destination city with a bonus unique to the game, a directed-expansion incentive that 1830 lacks (1830 has no destinations assigned to companies).

7. Privates with their own money-generating abilities
Beyond a fixed revenue stream as in 1830, some privates in 1870 have special abilities to generate extra income for their owner under certain game circumstances, adding an extra layer of personal optimization on top of running companies.

8. Rules base inspired by Tresham's 1829
1870 builds on the mechanics of 1829 (Tresham's own direct British predecessor) and adds its own layers, rather than deriving directly from the North American 1830.

9. Emphasis on stock manipulation
1870 is especially well known for the breadth and depth of its stock market game (buying, selling, redemption, discounted reissue, price protection), considered by many players one of the best in the entire 18xx family, richer in this respect than 1830.

10. Less survival pressure, more "expansive" game
Thanks to the size of the map and the financial protection tools, 1870 tends to be an experience where almost every company survives and thrives, in contrast with 1830, where it's common for some company to clearly fall behind or even fail outright.

1870 Railroading Across the Trans Mississippi — Schematic summary (vs 1830)

CONTEXT

• West of the Mississippi, very large map
• 10 public companies + 6 privates

STOCK MARKET

• Share price protection under certain circumstances
• Share redemption to get back under the certificate limit
• Share reissue at a 25% discount off the market price

EXPANSION

• Destination bonuses when connecting to the assigned city
• Privates with active income-generating abilities, not just fixed revenue

OVERALL TONE

• Large map → less direct competition, more companies end up profitable than in 1830