The point: If a game has a limit of (for example) 100 rounds, don't end it once 100 rounds end, but in a random round starting from 100 to 110 (doesn't have to be 10 rounds space, can be set by the one who starts the game).
Basically, allow the game to end in a random round within a given rage of rounds (for example, end it randomly between 20th round and 40th round)
Reason: I usually like to play standard rules/chained reinforcements with a bunch of people, the usual way to play a risk game, but a lot of times people start stacking and some sort of perpetual balance is achieved where if all the remaining players play safe and smart, nobody can win.
To avoid that situation where the game is prolonged indefinitely, you can use the round limit system - BUT, because people know it will end in a specific point, it affects the gameplay of players and they try to win those artificial 'round limit' win requirements rather than play the game naturally.
Ideally, you wouldn't know what's the round limit, mechanism would automatically determine that the game became pointless and it would end it, one with the most troops wins (as per current rules), but since that's not possible, game ending in a random round within a given range is a good alternative - it would reduce the poor game behavior I mentioned, make the players behave more naturally (albeit with more initiative because they know the game will end soon, but they don't know the exact round so there won't be any dirty calculated moves)
