Outline of a RunEdit
Every "run" in Risk of Rain starts out the same, with no way to save progress partway. The character is level 1 with no gold or items and has to obtain such during the playthrough. The run will continue until the player dies, quits, or wins the final level, at which point achievements/unlocks are saved and all experience, gold, and items are discarded. The player must balance item collection and level progress against the clock, as the difficulty increases with time. See Strategies for suggestions of going about this with the most likely chances of survival. Progressing through levels or activating teleporters too quickly can lead to underleveled/undergeared characters dying quickly, requiring more skill but sometimes resulting in simply being overrun. The random spawns and items add some spice, forcing players to be flexible in their playstyles.
Each map contains a Teleporter which must be found and then activated. A countdown timer will start and the spawn rate will increase, including at least one boss. The timer is 90 seconds on Drizzle and Rainstorm, and 120 seconds on Monsoon. When the countdown is complete, enemies will stop spawning. When no enemies are left, the teleporter can be activated to move to the next level, or the player can scour the map for any leftover item crates or shrines. Items and experience will be retained, and any leftover gold will be converted to XP points.
Beating the GameEdit
There is no "end" to Risk of Rain other than finishing a run by defeating the final boss. The game's replayability is enhanced by the fact that every run will typically unlock new items (increasing chances to survive next time), artifacts (to mutate the game's rules in many ways), or new characters to master. "Beating" it could possibly be described as achieving 100% of all unlocks.