AI

• Fixed crash when the AI simulates a fight between two units which can slow but aren't yet slowed, then simulates another fight for one of them in Monte Carlo mode (issue #3650).
• Experimental AI recruiting: fixed AI crash for unit type with unknown race
• Support for modifying the available AIs using cores:
  • New parameter default_ai_algorithm for setting the default AI
  • New parameter mp_rank for setting the order in which AIs appear in the MP computer player selection menu

• New option "Keep saved AI" when reloading games from the MP Create Game screen. Choosing this option prevents overwriting of the saved AI by the default AI. (issue #3791)
• Forest Animals Micro AI: fix AI crash when using custom rabbit hole image
• Fix Lua AIs using the ai.stopunit_*() functions potentially creating infinite candidate action loops

Campaigns

• Dead Water:
  • S12: Slightly rebalanced enemy reinforcements and ai gold

• Descent Into Darkness:
  • Allow converting L3 necromancers to liches from S12 onwards (issue #3165).
  • Added an alternative method of completing the campaign (issue #3167).
  • S8, S9 (A Small Favor II & III): Clarify objectives. (PR #3711)
  • S8 (A Small Favor II): Fixed units created via the plague ability not available in S9. (PR #3711)

• Sceptre of Fire:
  • S1&2: increased difficulty
  • S6: additional guards for the elves

• Secrets of the Ancients:
  • S01 Slipping Away: It is now obvious that the wild animals cannot cross the fences.
  • S02 Dark Business: Simplify scenario by removing the temporary invisible starting keep.
  • S05 Blackwater: Additional dialog from Ardonna at the start.
  • S11 Battleground: Ghosts are now able to be recruited after the scenario is complete.
  • S15 Mountain Pass: Bird bones moves so bird is easier to keep alive when discovered.
  • S21 Against the World: Leader of the elves is now same elf from S12.
  • S21 Against the World: Adjustment so player doesn't have to chase down some leaders at the end.
  • Proper animation for finding the bird bones.
  • Newly made liches will now receive a move point upon transformation if they weren't recalled. this turn and haven't moved yet.

• The Hammer of Thursagan
  • S12 'The Underlevels': redesigned with completely new map and scenario

• Northern Rebirth:
  • Fix loyal units obtained in S7 costing upkeep (introduced in 1.14.5)
  • S13: Improvement to the AIs

• The Rise of Wesnoth:
  • S15: victory text is not used upon hero death
  • S17d: enemy units are killed upon victory except for bats
  • S22: cuttlefish now have the loyal icon

• The South Guard:
  • Revised scenario and story dialogue.
  • Reworked and rebalanced all scenario and map designs.
  • Removed S6a 'Tidings Good and Ill'.

• Tutorial:
  • S2: Wolf riders are not initially recruited, to not hinder the player from reaching the island in time

Language and i18n

• Updated translations: British English, Chinese (Simplified), Chinese (Traditional), Czech, French, German, Italian, Japanese, Lithuanian, Russian, Scottish Gaelic, Slovak, Spanish, Ukrainian.

Lua API

• Fix wesnoth.set_dialog_callback calling the function immediately when used in the previous callback. (issue #3794)
• Fix wesnoth.set_dialog_value not triggering re-layout. (issue #3572)
• wml.tostring() now outputs a string that can be parsed back to WML without loss of data.

Miscellaneous and bug fixes

• Fix crash with custom themes on desktop PCs. (issue #3599)
• Add --campaign-skip-story command line switch for skipping directly to turn 1. (issue #3472)
• Remove --data option, --data-path has the same functionality.
• Fix documentation of --render-image command line switch. (issue #3568)
• Update manpage with options previously only documented by wesnoth --help.
• Fix wrong ordering for BW / BF years, for example in Play a Campaign when sorted by date. (issue #3187)
• GUI.pyw can now terminate a running maintenance script
• Fix SDL_DestroyRenderer assertion failure under XMonad. (part of issue #3716)
• Fix map item names not being translated in the scenario editor.
• Usernames specified in the MP UI and command line are now stripped of leading and trailing whitespace, including newlines.
• Show ability of a selected unit as active/inactive with respect to mouseover hex. (issue #3912)
• macOS: Wesnoth now uses the app sandboxing feature, which means there is a new location for saves. All saves will be migrated during first launch automatically. For info about backwards compatibility see: https://gist.github.com/hrubymar10/eb5afd896f933a46fac344ced940e020
• Many units lacking animations now have at least a defense animations

Multiplayer server

• Fix stale temporary bans continuing to have an effect on players until cleared by phpBB on the next ban/unban operation.

Packaging

• new scons option, intended to be used when building releases inside a git repo: autorevision=False
• Fix build with Boost 1.69. (issue #3646)
• Fix build with Pango 1.43. (issue #3840)

User interface

• Fix regression: Game Load screen would not select 1.12 savegames. (issue #3561)
• Fix regression: the in-game "Observers" icon (an eye) was covered by the minimap. (issue #3543)
• Increase step size when clicking sliders in the MP Create Game dialog. (issue #3552)
• Fix overlapping top bar elements with small screen resolutions. (issue #3714)
• Don't scroll to an invisible unit that recruits another invisible unit. (issue #3559)
• When a recruited unit is fogged, scroll to the recruiting unit and play recruit animation. (issue #3577)
• Fix line breaks in first statistics line in unit type pages in the help. (issue #3256)
• Don't scroll to an enemy unit that teleports to or from an invisible hex. (PR #3578)
• Don't show in the sidebar the time of day schedule of a shrouded hex. (PR #3638)
• Game Load screen gracefully handles savefiles that can't be parsed. (issue #3652)
• The sidebar now shows alignment and damages as they would be on the hex under the mouse, rather than at the unit's current location. (PR #3642)
• When a unit has multiple statuses (slowed/poisoned/invisible/etc), the sidebar shows all of them, not just the first. (issue #3197)
• Fixed being able to dismiss a game lobby by pressing Esc.
• Fixed multiple severe issues in the classic theme.
• The "Attack Enemy" dialog now shows inactive weapon specials in gray. (PR #3686)
• Taking screenshots in title screen is possible again (issue #3235)
• The "Recruit Unit" dialog is searchable by unit type name. (PR #3787)
• Add text filter to hotkeys preferences. (PR #3759)
• Hide leader in status table if it's unfogged but invisible. (PR #3854)
• macOS: Dark GUI on macOS Mojave and later when dark appearance is enabled.