fallout2-ce/SFALL_COMPATIBILITY.md

Sfall Compatibility

This document tracks Fallout 2 CE compatibility with sfall. This is for modders who need to know which Sfall features work in CE.

For now, this covers opcodes/metarules, and hooks. In the future, it will include other ways of modifying the engine (like ini files), and other Sfall-specific behaviour.

HRP EDG Scroll-Blocker Support

CE supports the .edg file format from the HRP (High Resolution Patch), which defines per-map scroll boundaries and square-level render clipping.

How it works in CE:

• On map load, maps/<mapname>.edg is read if present. Missing file = silent fallback to the scroll-blocker object system.
• The .edg file defines per-elevation rectangle boundary zones. Multiple chained zones per elevation are supported.
• When loaded, these zones are used for both scroll blocking and visible area clipping (black bars), replacing both vanilla scroll blocking and CE hi-res stencil system.
• v2 EDG files also contain a SquareRect that defines "Angled edges", or square-grid stencil. This is also supported.

Settings (ddraw.ini → fallout2.cfg / game.cfg)

Settings previously read from ddraw.ini have been moved into standard CE config files.

Most settings that control game behavior (premade characters, extra message files, combat tweaks, worldmap, etc.) have been moved into <DAT>/config/game.cfg, which is a content-mod config file intended to be overridden by mods. See that file for the full list with descriptions.

The following settings were moved into fallout2.cfg instead:

ddraw.ini section	ddraw.ini key	fallout2.cfg section	fallout2.cfg key
Misc	SkipOpeningMovies	ui	skip_opening_movies
Misc	DisplayKarmaChanges	ui	display_karma_changes
Misc	DisplayBonusDamage	ui	display_bonus_damage
Misc	NumbersInDialogue	ui	numbers_in_dialogue
Misc	AutoQuickSave	ui	auto_quick_save
Main	EnableHighResolutionStencil	ui	enable_high_resolution_stencil
Misc	ConsoleOutputPath	debug	console_output_path
Misc	GaplessMusic	sound	gapless_music
Misc	ScreenshotsFormat	system	screenshots_format
Misc	UseWalkDistance	qol	use_walk_distance
Misc	AutoOpenDoors	qol	auto_open_doors

The following settings were moved into <DAT>/config/game.cfg:

ddraw.ini section	ddraw.ini key	game.cfg section	game.cfg key
Misc	StartingMap	start	map
Misc	StartXPos	start	worldmap_x
Misc	StartYPos	start	worldmap_y
Misc	ViewXPos	start	worldmap_view_x
Misc	ViewYPos	start	worldmap_view_y
Misc	StartGDialogFix	dialog	start_gdialog_fix
Misc	DisableSpecialMapIDs	maps	disable_special_map_ids

Opcodes / Metarules

See https://sfall-team.github.io/sfall/ for documentation on specific functions.

Group	Opcodes In Group	Compatibility	Notes
Direct memory access	read_byte,short,int,string write_byte,short,int,string call_offset_vX	🚫	Not possible. Open an issue if you need functionality not covered by other opcodes.
Stats	get/set_pc_base_stat get/set_pc_extra_stat get/set_critter_base_stat get/set_critter_extra_stat	✅	CE uses engine stat helpers here instead of sfall's direct proto-field behavior, so derived-stat update behavior can differ.
Stats / Alter min/max	get/set_stat_min/max set_pc_stat_min/max set_npc_stat_min/max	not implemented	-
Skills	get/set_critter_skill_points get/set_available_skill_points set_skill_max set_critter_skill_mod set_base_skill_mod mod_skill_points_per_level	not implemented	-
Graphics	graphics_funcs_available force_graphics_refresh get_screen_width get_screen_height set_palette	implemented: only get_screen_width, get_screen_height	-
Shaders	load_shader free_shader activate_shader deactivate_shader set/get_shader_*	🚫	likely will not implement direct compatibility
Perks and traits	set_perk_image set_perk_* set_pyromaniac_mod apply_heaveho_fix set_swiftlearner_mod has/set_fake_perk has/set_fake_trait set_selectable_perk set_perkbox_title show/hide_real_perks perk_add_mode clear_selectable_perks add/remove_trait seq_perk_freq	not implemented	-
Virtual file system	fs_create fs_copy fs_find fs_read/write_* fs_delete fs_size fs_pos fs_seek fs_resize	🚫	Open an issue if you have a use case for these
Combat / Knockback	set_weapon_knockback set_target_knockback set_attacker_knockback remove_weapon_knockback remove_target_knockback remove_attacker_knockback	not implemented	-
Maps and encounters	in_world_map force_encounter{_with_flags} set_map_time_multi get/set_map_enter_position exec_map_update_scripts get/set_terrain_name set_town_title get/set_can_rest_on_map set_rest_heal_time set_rest_mode set_worldmap_heal_time	implemented: in_world_map, force_encounter, force_encounter_with_flags, set_map_time_multi, get_terrain_name, set_terrain_name	-
Maps and encounters / Worldmap	get_world_map_x/y_pos set_world_map_pos	✅	-
Audio	play_sfall_sound stop_sfall_sound	✅	play_sfall_sound currently supports .acm, .wav, .ogg formats, and can load from .dat archives. .mp3 is not yet supported.
Combat / Weapons and ammo	get/set_weapon_ammo_pid get/set_weapon_ammo_count	✅	-
Sfall / Version	sfall_ver_major sfall_ver_minor sfall_ver_build	✅	CE currently reports 4.3.4
Utility / Math	log, exponent, round, sqrt, abs, sin, cos, tan, arctan, ceil, ^, floor2, div	✅	-
Keyboard and mouse	key_pressed tap_key get_mouse_x/y get_mouse_buttons	✅	-
Lists	list_begin list_next list_end list_as_array party_member_list	✅	-
Explosions	set_attack_explosion_pattern set_attack_explosion_art set_attack_explosion_radius set_attack_is_explosion_fire set_explosion_radius set_dynamite_damage set_plastic_damage get_explosion_damage set_explosion_max_targets item_make_explosive	✅ except item_make_explosive	-
Animations	reg_anim_combat_check reg_anim_destroy reg_anim_animate_and_hide reg_anim_light reg_anim_change_fid reg_anim_take_out reg_anim_turn_towards reg_anim_callback reg_anim_animate_and_move	✅ except reg_anim_callback	-
Art and appearance	art_exists art_frame_data refresh_pc_art art_cache_clear	✅	-
Tiles and paths	get_tile_fid tile_under_cursor tile_light tile_get_objs tile_refresh_display obj_blocking_tile tile_by_position get_tile_ground_fid get_tile_roof_fid obj_blocking_line path_find_to objects_in_radius	✅	-
Utility	sprintf typeof atoi atof	✅	-
Utility / Strings	string_split substr strlen charcode get_string_pointer string_find string_find_from string_format string_format_array string_replace string_to_case string_compare	✅	get_string_pointer is deprecated and intentionally omitted.
Interface / Tags	show_iface_tag hide_iface_tag is_iface_tag_active set_iface_tag_text add_iface_tag	✅	Legacy BoxBarCount, BoxBarColors ddraw.ini settings not supported.
Global variables	set_sfall_global get_sfall_global_int get_sfall_global_float	✅ except get_sfall_global_float	Current CE storage is int-backed; set_sfall_global stores integer values
Hooks / Hook functions	init_hook get_sfall_arg get_sfall_args get_sfall_arg_at set_sfall_return set_sfall_arg register_hook register_hook_proc register_hook_proc_spec	✅	See below for implemented hooks. init_hook is deprecated and will not be implemented. register_hook_proc and register_hook_proc_spec both add hooks to the end of the hook list, instead of beginning and end, respectively.
Arrays / Array functions	create_array temp_array fix_array get/set_array resize_array free_array scan_array len_array save/load_array array_key arrayexpr	✅	-
Perks and traits / NPC perks	set_fake_perk_npc set_fake_trait_npc set_selectable_perk_npc has_fake_perk_npc has_fake_trait_npc	not implemented	-
Global scripts / Global script functions	set_global_script_repeat set_global_script_type available_global_script_types	✅ except available_global_script_types	-
Combat	attack_is_aimed block_combat force_aimed_shots disable_aimed_shots get_attack_type get/set_bodypart_hit_modifier combat_data get/set/reset_critical_table get_last_target get_last_attacker set_critter_burst_disable get/set_critter_current_ap set_spray_settings get/set_combat_free_move	✅ except block_combat, force_aimed_shots, disable_aimed_shots, get_last_target, get_last_attacker, set_spray_settings	-
Car	set_car_current_town car_gas_amount set_car_intface_art	implemented: all except set_car_intface_art	-
Interface / Windows and images	interface_art_draw interface_print draw_image{_scaled} get_window_under_mouse create_win get_window_attribute message_box set_window_flag win_fill_color interface_overlay dialog_message get_text_width hide_window show_window create_message_window	✅ except interface_print, interface_overlay	-
Interface / Outline	outlined_object get_outline set_outline	✅	-
Interface / Main interface	intface_is_hidden intface_redraw intface_hide intface_show set_quest_failure_value	implemented: only intface_redraw	intface_redraw only supports the zero-argument form; the optional-argument path is explicitly unimplemented.
Interface / Inventory	display_stats inventory_redraw critter_inven_obj2 get_current_inven_size item_weight	✅ except get_current_inven_size	-
Interface / Cursor	get/set_cursor_mode	✅	-
Locks	lock_is_jammed unjam_lock set_unjam_locks_time	not implemented	-
INI settings	get_ini_setting get_ini_string get_ini_section get_ini_sections get_ini_config get_ini_config_db set_ini_setting	✅	modified_ini is intentionally omitted as deprecated.
Objects and scripts	set_self set_dude_obj real_dude_obj remove_script get/set_script obj_is_carrying_obj loot_obj dialog_obj obj_under_cursor get/set_object_data get/set_flags set_unique_id set_scr_name obj_is_openable get/set_proto_data get_object_ai_data	✅ except set_dude_obj, set_scr_name	get/set_object_data maps supported object and C_ATTACK_* offsets instead of exposing arbitrary raw memory offsets.
Other / Game management	set_movie_path stop/resume_game mark_movie_played game_loaded get_game_mode get_uptime signal_close_game	implemented: game_loaded, get_game_mode, get_uptime, signal_close_game	-
Gameplay tweaks	set_pickpocket_max set_hit_chance_max set_xp_mod set_critter_hit_chance_mod set_base_hit_chance_mod set_hp_per_level_mod gdialog_get_barter_mod get/set_unspent_ap_bonus get/set_unspent_ap_perk_bonus set_base_pickpocket_mod set_critter_pickpocket_mod get/set_inven_ap_cost set_drugs_data get_kill_counter mod_kill_counter set_pipboy_available	implemented: gdialog_get_barter_mod, get/set_unspent_ap{_perk}_bonus, get/set_inven_ap_cost	-
NPCs	inc_npc_level get_npc_level npc_engine_level_up	not implemented	-
Hero Appearance	set_dm/df_model hero_select_win set_hero_race set_hero_style	not implemented	-
Events	add_g_timer_event remove_timer_event create_spatial spatial_radius	not implemented	-
Other	get_year active_hand toggle_active_hand get/set_viewport_x/y get_light_level message_str_game sneak_success unwield_slot add_extra_msg_file get_metarule_table metarule_exist	✅ except get/set_viewport_x/y, sneak_success	input_funcs_available, nb_create_char are deprecated in sfall and intentionally absent in CE. add_extra_msg_file does not support the explicit fileNumber form in CE.

Hooks

Hook	ID	Compatibility	Notes
ToHit	HOOK_TOHIT	✅	-
AfterHitRoll	HOOK_AFTERHITROLL	✅	Overriding defender leaves a lot of attack variables in previous state (e.g. distance, ->oops, roundsHitMainTarget)
CalcAPCost	HOOK_CALCAPCOST	✅	-
DeathAnim1	HOOK_DEATHANIM1	🚫	Use DEATHANIM2 instead
DeathAnim2	HOOK_DEATHANIM2	✅	-
CombatDamage	HOOK_COMBATDAMAGE	✅	-
OnDeath	HOOK_ONDEATH	✅	-
FindTarget	HOOK_FINDTARGET	🚫	(maybe)
UseObjOn	HOOK_USEOBJON	✅	-
UseObj	HOOK_USEOBJ	✅	CE notes an sfall-matching inconsistency around return code 2 behavior between interface contexts.
RemoveInvenObj	HOOK_REMOVEINVENOBJ	✅	-
BarterPrice	HOOK_BARTERPRICE	✅	-
ItemDamage	HOOK_ITEMDAMAGE	✅	-
MoveCost	HOOK_MOVECOST	✅	-
AmmoCost	HOOK_AMMOCOST	✅	Requires check_weapon_ammo_cost=1 if you want pre-attack ammo validation to respect per-shot/per-round overrides.
KeyPress	HOOK_KEYPRESS	✅	Third hook arg is currently 0; CE doesn't use VK codes.
MouseClick	HOOK_MOUSECLICK	✅	-
UseSkill	HOOK_USESKILL	✅	-
Steal	HOOK_STEAL	✅	-
WithinPerception	HOOK_WITHINPERCEPTION	✅	-
InventoryMove	HOOK_INVENTORYMOVE	✅	-
InvenWield	HOOK_INVENWIELD	✅	-
AdjustFID	HOOK_ADJUSTFID	✅	Second hook arg currently matches the first because CE has no internal FID modifiers like Hero Appearance.
CombatTurn	HOOK_COMBATTURN	✅	-
StdProcedure	HOOK_STDPROCEDURE	✅	-
StdProcedureEnd	HOOK_STDPROCEDURE_END	✅	-
CarTravel	HOOK_CARTRAVEL	🚫	-
SetGlobalVar	HOOK_SETGLOBALVAR	🚫	-
RestTimer	HOOK_RESTTIMER	✅	CE is slightly more strict: only ret0 == 1 interrupts. Ticks wrap every 6.8y; do not rely on them for absolute game time.
GameModeChange	HOOK_GAMEMODECHANGE	✅	-
UseAnimObj	HOOK_USEANIMOBJ	🚫	Et tu; (maybe)
ExplosiveTimer	HOOK_EXPLOSIVETIMER	✅	-
DescriptionObj	HOOK_DESCRIPTIONOBJ	🚫	Et tu
UseSkillOn	HOOK_USESKILLON	✅	-
OnExplosion	HOOK_ONEXPLOSION	🚫	(maybe)
SubCombatDamage	HOOK_SUBCOMBATDAMAGE	🚫	(maybe)
SetLighting	HOOK_SETLIGHTING	🚫	Et tu; (maybe)
Sneak	HOOK_SNEAK	🚫	-
TargetObject	HOOK_TARGETOBJECT	🚫	(maybe)
Encounter	HOOK_ENCOUNTER	✅	-
AdjustPoison	HOOK_ADJUSTPOISON	🚫	(maybe)
AdjustRads	HOOK_ADJUSTRADS	🚫	(maybe)
RollCheck	HOOK_ROLLCHECK	🚫	-
BestWeapon	HOOK_BESTWEAPON	🚫	-
CanUseWeapon	HOOK_CANUSEWEAPON	✅	-
BuildSfxWeapon	HOOK_BUILDSFXWEAPON	🚫	-