For example, there's still permadeath, but you can disable it or play in “Adventure mode”, where you can die a few times before your character is erased.

ToME also makes selective use of randomness.
Its world map, towns, NPCs and quests are fixed, allowing for a quality far beyond that of traditional roguelikes. It even offers choices and consequences: there's a faction that hates magic due to past events and will attack magic-users on sight – but also share secret anti-magic techniques if your character renounces magic forever. Another option is to ally yourself with renegade mages and destroy said faction.

Dungeons blend random layouts, enemies and treasures with fixed themes, key rooms and bosses. This gives them a lot of personality – you'll follow
giant sandworms as they dig tunnels, battle in space, free slaves, dive underwater, race against time, etc.

Another unusual mechanic is how most races and classes have unique starting points and quests, but must be unlocked first. Say you start as a Dwarf Berserker – you'll begin your adventures in the Dwarven kingdom, learn about their culture, do some race and class-specific quests then venture into the world map. If you're lucky, by the time you die you'll have done something special and unlocked a new race or class, and can now, for example, play as an Elven Archmage, which starts in a different area with different quests.

The game currently has 16 races and 35 classes, offering several widely different playstyles. Each class has a set of skill trees that slowly unlocks as you level up, providing direct damage skills and passive bonuses, but there's also many “utility” abilities: teleporting, redirecting damage, raising walls, magic shields, etc. Instead of random potions and scrolls, you're given a clearly defined set of versatile tools and must manage their resources and cooldowns wisely.