Games like Only Fortress
Games like Only Fortress include Total War: WARHAMMER, Kingdom Heroes 8, Albion Online, Kenshi, and Crown and Adventure. We matched them by the tags players give Only Fortress on Steam (RPG, Strategy, MMORPG, RTS, and Sandbox): closest matches first, and among equally close ones the better-known games.

Total War: WARHAMMER
Shared: RPG · Strategy · RTS

Kingdom Heroes 8
Shared: RTS · Strategy · Real Time Tactics

Albion Online
Shared: MMORPG · RPG · Sandbox

Kenshi
Shared: RPG · Sandbox · Strategy RPG

Crown and Adventure
Shared: Sandbox · RPG · Real Time Tactics

Trove
Shared: MMORPG · Sandbox · RPG

Crusader Kings III
Shared: Strategy · RPG · Sandbox

Stronghold: Definitive Edition
Shared: Strategy · RTS · Real Time Tactics

Game of Thrones Winter is Coming
Shared: Strategy · RPG · RTS

The Banner Saga
Shared: RPG · Strategy · Strategy RPG

The Last Spell
Shared: Strategy · RPG · Strategy RPG

Stronghold Crusader: Definitive Edition
Shared: Strategy · Real Time Tactics · Sandbox

Viking Rise
Shared: RPG · Strategy · Strategy RPG

Crusader Kings II
Shared: Strategy · RPG · Sandbox

Stoneshard
Shared: RPG · Strategy · Pixel Graphics

Mount & Blade II: Bannerlord
Shared: Strategy · RPG · Sandbox

Mount & Blade: Warband
Shared: RPG · Strategy · Sandbox

Heroes' Vow: Three Kingdoms
Shared: Strategy · RPG · Strategy RPG

Gladiator Guild Manager
Shared: Strategy · RPG · Strategy RPG

The Scroll of Taiwu : Beyond The Dome
Shared: RPG · Sandbox · Strategy

Symphony of War: The Nephilim Saga
Shared: RPG · Tactical RPG · Strategy RPG

Total War: WARHAMMER II
Shared: Strategy · RTS · Real Time Tactics

Broken Arrow
Shared: Strategy · RTS · Real Time Tactics

Heroes of the Three Kingdoms 7
Shared: Strategy · Strategy RPG · RTS