In a one-player game, you can write a competent, consistent computer player. Then use the standard deviation in performance of that bot over many runs as a measure of chance in the game.
In a multiplayer game, write a skilled/optimum player and a naive/basic player. The win-percentage of the weak bot can be a good measure of chance.
Many roguelikes (a category FTL is usually included in) have bots which facilitate this kind of analysis. But since competent bots are sometimes difficult to write well, some games also use "scummers" and/or stats modules which generate millions of randomly-generated levels and compute difficulty or reward heuristics for each, ensuring that the st. dev. is within desired ranges. If the heuristics are good, this can be sufficient.
Another option in a hosted game or one that can phone home is to have real-live players be the guinea pigs instead of the bots. Same basic principles apply.
In a multiplayer game, write a skilled/optimum player and a naive/basic player. The win-percentage of the weak bot can be a good measure of chance.
Many roguelikes (a category FTL is usually included in) have bots which facilitate this kind of analysis. But since competent bots are sometimes difficult to write well, some games also use "scummers" and/or stats modules which generate millions of randomly-generated levels and compute difficulty or reward heuristics for each, ensuring that the st. dev. is within desired ranges. If the heuristics are good, this can be sufficient.
Another option in a hosted game or one that can phone home is to have real-live players be the guinea pigs instead of the bots. Same basic principles apply.