Microsoft has updated the rules regarding the total amount of Achievements and gamerscore that Xbox 360 games can award to players.
Although the company has not officially said so, several unconnected development sources have confirmed to Eurogamer that the upper limits are 80 Achievements and 1750 gamerscore respectively.
The specific rules are that a boxed game must offer between five and 50 Achievements for a total of 1000 gamerscore, while up to 30 Achievements can be offered via downloadable content for a maximum of 750 gamerscore.
According to UK sources, the current software development kit documentation refers to this, but also contradicts itself in a few places. However, developers understand that the limits have changed and are working to the new certification requirements for future downloadable content.
Previously, developers were limited to 1000G on the disc and 250G in downloadable content, but games like Halo 3 most notably and also Fallout 3 have since convinced Microsoft to go further.