| OBSCENE_PICTOGRAM | Content.ItemKindEmbed |
| ObscureAs | Game.LambdaHack.Content.TileKind |
| obscureAs | Game.LambdaHack.Common.Tile |
| occupiedBigLvl | Game.LambdaHack.Common.Level |
| occupiedProjLvl | Game.LambdaHack.Common.Level |
| odd | Game.LambdaHack.Core.Prelude |
| Odds | Game.LambdaHack.Content.ItemKind |
| oddsDice | Game.LambdaHack.Core.Random |
| oexistsGroup | Game.LambdaHack.Definition.ContentData |
| offsetOverlay | Game.LambdaHack.Client.UI.Overlay |
| offsetOverlayX | Game.LambdaHack.Client.UI.Overlay |
| ofoldlGroup' | Game.LambdaHack.Definition.ContentData, Game.LambdaHack.Common.Kind |
| ofoldlWithKey' | Game.LambdaHack.Definition.ContentData, Game.LambdaHack.Common.Kind |
| OftenActor | Game.LambdaHack.Content.TileKind |
| OftenItem | Game.LambdaHack.Content.TileKind |
| oimapVector | Game.LambdaHack.Definition.ContentData, Game.LambdaHack.Common.Kind |
| oisSingletonGroup | Game.LambdaHack.Definition.ContentData, Game.LambdaHack.Common.Kind |
| okind | Game.LambdaHack.Definition.ContentData, Game.LambdaHack.Common.Kind |
| OKX | Game.LambdaHack.Client.UI.Slideshow |
| okxItemLorePointedAt | Game.LambdaHack.Client.UI.HandleHelperM |
| okxsN | Game.LambdaHack.Client.UI.KeyBindings |
| olength | Game.LambdaHack.Definition.ContentData, Game.LambdaHack.Common.Kind |
| omapVector | Game.LambdaHack.Definition.ContentData, Game.LambdaHack.Common.Kind |
| omemberGroup | Game.LambdaHack.Definition.ContentData, Game.LambdaHack.Common.Kind |
| OnCombine | Game.LambdaHack.Content.ItemKind |
| onCombineEffect | Game.LambdaHack.Content.ItemKind |
| oneM | Game.LambdaHack.Common.Misc |
| OneOf | Game.LambdaHack.Content.ItemKind |
| oneOf | Game.LambdaHack.Core.Random |
| only | Game.LambdaHack.Client.AI.Strategy |
| onlyMinorEffects | Game.LambdaHack.Common.ItemAspect |
| onlyRegisterItem | Game.LambdaHack.Server.ItemM |
| OnSmash | Game.LambdaHack.Content.ItemKind |
| onSmashEffect | Game.LambdaHack.Content.ItemKind |
| onSmashOrCombineEffect | Game.LambdaHack.Content.ItemKind |
| OnUser | Game.LambdaHack.Content.ItemKind |
| OpenTo | Game.LambdaHack.Content.TileKind |
| openTo | Game.LambdaHack.Common.Tile |
| OpenWith | Game.LambdaHack.Content.TileKind |
| OPEN_STAIRCASE | Content.PlaceKind |
| opick | Game.LambdaHack.Definition.ContentData, Game.LambdaHack.Common.Kind |
| or | Game.LambdaHack.Core.Prelude |
| Ord | Game.LambdaHack.Core.Prelude |
| Ordering | Game.LambdaHack.Core.Prelude |
| ORDINARY_STAIRCASE_DOWN | Content.TileKind |
| ORDINARY_STAIRCASE_UP | Content.TileKind |
| OrEffect | Game.LambdaHack.Content.ItemKind |
| orEffect | Game.LambdaHack.Content.ItemKind |
| organBenefit | Game.LambdaHack.Client.Preferences |
| organs | Content.ItemKindOrgan |
| organsGN | Content.ItemKindOrgan |
| organsGNSingleton | Content.ItemKindOrgan |
| originPoint | Game.LambdaHack.Common.Point |
| otherItemContent | Content.ItemKind |
| otherwise | Game.LambdaHack.Core.Prelude |
| ouniqGroup | Game.LambdaHack.Definition.ContentData, Game.LambdaHack.Common.Kind |
| oursExploringAssocs | Game.LambdaHack.Client.BfsM |
| Outcome | Game.LambdaHack.Content.ModeKind |
| OUTDOOR_CLOSED_STAIRCASE | Content.PlaceKind |
| OUTDOOR_ESCAPE_DOWN | Content.PlaceKind |
| OUTDOOR_OUTER_FENCE | Content.TileKind |
| OUTDOOR_TINY_STAIRCASE | Content.PlaceKind |
| OUTDOOR_WALLED_STAIRCASE | Content.PlaceKind |
| overheadActorTime | Game.LambdaHack.Server.PeriodicM |
| Overlay | Game.LambdaHack.Client.UI.Overlay |
| overlayFrame | Game.LambdaHack.Client.UI.Frame |
| OverlaySpace | Game.LambdaHack.Client.UI.Frame |
| overlayToSlideshow | Game.LambdaHack.Client.UI.SlideshowM |
| override2PlaceKind | Game.LambdaHack.Content.PlaceKind |
| overridePlaceKind | Game.LambdaHack.Content.PlaceKind |
| OverrideTut | Game.LambdaHack.Client.UI.HumanCmd |
| overrideTutHuman | Game.LambdaHack.Client.UI.HandleHumanLocalM |