ADOM (Ancient Domains Of Mystery) is one of the most successful roguelike games ever created, boasting a brilliant mix of story, RPG, exploration, and intensely strategic & flexible combat. The Steam version adds various features like achievements, difficulty level customization & play modes.
You face a 9-headed hydra. Your sword cuts 5 heads in each swipe (never less), which kills a 5-headed hydra, but a larger one will regrow 2 heads after each swipe. Your scythe cuts exactly 7, but 10 grow back if the hydra lives. Can you kill the hydra? Or better to explore to find more arms first?