This is an incomplete list of game differences in comparision to v1.3.
See doc/list_pbxnum.txt for optional game differences.
See doc/usage_classic.txt for UI differences.

Much of this file is based on the readme from the unofficial v1.40m patch.

- the game makes an undo save (slot 8) on every next turn click, run with -noundo if you do not want this
- the game makes yearly saves on (1oom_save_YYYY.bin) every next turn click, if allowed to with -yearsave
- the game is deterministic by default
- saving and reloading does not affect game state
- fleets can not be sent to the planet they are orbiting (redirecting departing fleets back to orbit is still possible)
- multiple fleets sent to same destination on the same turn are combined if they have the same speed
- fixed "bug" where on a given year only one scouted artifact planets gave new tech
- the number of build finished messages per turn is no longer limited to 10 per category
- fixed weird behaviour when space monsters attack colonized Orion
- fixed AI-AI tech trades where the tech was not owned by either party
- all Advanced Technology are available for research
- espionage messages can show the framed or unknown race instead of always leaking the actual spy

- ETA calculations take nebulas into account correctly
- annoying bug / cheat when a fleet with bioweapons automatically bombed an enemy planet while orbiting is gone for good
- entering the general "threaten / break treaty" dialogue no more equals to a large temporary diplomatic penalty
- the discovery percentages on tech screen are no more only 1/2 of the true probability of a tech hit
- Psilon leader "Zygot  " name correction (extra whitespace trimmed from all names)
- the AI now uses the right race and the right objective when it takes decision about where to allocate the research points
- the spies you educate on the same turn against different races are no more overpriced
- breaking a NAP / alliance no more positively contributes to your relations with the AIs
- 8th stargate bug corrected (no ship maintenance overflow)

- changes in Classic+ AI:
    - first tech costs are calculated using the same formula as the rest
    - cash tributes work as described in OSG instead of not at all
    - AI checks the correct mood variable when asked for a peace treaty
    - AI-AI stop war check uses the same relation value as the make treaty/trade checks instead of the last diplo message subtype
    - AI huge, armored ships now cannot cause a negative overflow
    - 4th colony ship curse removed
    - ignore journey length for closest in-range colony ship
    - do not try to send one colony ship to multiple destinations
    - AIs now actually take their treaties in consideration when asked to declare war on their allies
    - AI clears his spies' missions when succesfully threatened
    - AI does not blame both parties for breaking a treaty
    - the AI now uses the correct radius of action during its decision making
    - a war sparked by capturing or destroying a colony is considered to be started by the attacker
    - a small issue concerning the change in AI defense and ship production when too many MBases on a planet has been corrected
    - Bulrathi orbital bombardment decisions corrected to reflect their race bonus
    - Alkari and Mrrshan bonus for AI-AI combat corrected to reflect their race bonus
    - battle AI miss chance accumulation fixed; AI is less/more optimistic about missile/beam weapon damage
    - battle AI checks shield halving properly, does not check for target's Oracle or any Oracle for missiles
    - battle AI will not retreat due to doom stack damage estimate overflow
    - AI does not go into panic ship building mode on planets with incoming allied fleets
    - AI-AI battles destroy missile bases

- the game has multiplayer (only local/hotseat for now); multiplayer differences to single player:
    - player diplomat is always up for audience except during the final war
    - when asked by other player to join a treaty, a player can ask for tech to sweeten the deal from those the spies have reported to exist
    - each player can accept/refuse the council ruling; the final war alliances are based on refusals
