diff --git a/src/cata_string_consts.h b/src/cata_string_consts.h
index 2420140717ec4..68c30765ae4f5 100644
--- a/src/cata_string_consts.h
+++ b/src/cata_string_consts.h
@@ -398,7 +398,6 @@ static const efftype_id effect_weed_high( "weed_high" );
 static const efftype_id effect_winded( "winded" );
 static const efftype_id effect_zapped( "zapped" );
 
-
 static const trait_id trait_ACIDBLOOD( "ACIDBLOOD" );
 static const trait_id trait_ACIDPROOF( "ACIDPROOF" );
 static const trait_id trait_ADDICTIVE( "ADDICTIVE" );
@@ -758,7 +757,6 @@ static const mongroup_id GROUP_WORM( "GROUP_WORM" );
 static const mongroup_id GROUP_ZOMBIE( "GROUP_ZOMBIE" );
 static const mongroup_id GROUP_ZOMBIE_COP( "GROUP_ZOMBIE_COP" );
 
-
 static const mtype_id mon_amigara_horror( "mon_amigara_horror" );
 static const mtype_id mon_ant( "mon_ant" );
 static const mtype_id mon_ant_acid_larva( "mon_ant_acid_larva" );
@@ -824,6 +822,7 @@ static const mtype_id mon_hologram( "mon_hologram" );
 static const mtype_id mon_horse( "mon_horse" );
 static const mtype_id mon_hound_tindalos_afterimage( "mon_hound_tindalos_afterimage" );
 static const mtype_id mon_jabberwock( "mon_jabberwock" );
+static const mtype_id mon_laserturret( "mon_laserturret" );
 static const mtype_id mon_leech_blossom( "mon_leech_blossom" );
 static const mtype_id mon_leech_root_drone( "mon_leech_root_drone" );
 static const mtype_id mon_leech_root_runner( "mon_leech_root_runner" );
@@ -835,6 +834,7 @@ static const mtype_id mon_marloss_zealot_m( "mon_marloss_zealot_m" );
 static const mtype_id mon_mink( "mon_mink" );
 static const mtype_id mon_moose( "mon_moose" );
 static const mtype_id mon_muskrat( "mon_muskrat" );
+static const mtype_id mon_null( "mon_null" );
 static const mtype_id mon_opossum( "mon_opossum" );
 static const mtype_id mon_otter( "mon_otter" );
 static const mtype_id mon_pheasant( "mon_pheasant" );
@@ -1349,7 +1349,6 @@ static const zone_type_id zone_type_NO_AUTO_PICKUP( "NO_AUTO_PICKUP" );
 static const zone_type_id zone_type_VEHICLE_DECONSTRUCT( "VEHICLE_DECONSTRUCT" );
 static const zone_type_id zone_type_VEHICLE_REPAIR( "VEHICLE_REPAIR" );
 
-
 static const zone_type_id z_camp_food( "CAMP_FOOD" );
 static const zone_type_id z_camp_storage( "CAMP_STORAGE" );
 static const zone_type_id z_loot_unsorted( "LOOT_UNSORTED" );
diff --git a/src/character.cpp b/src/character.cpp
index 3b1e308e2c442..5a2b602d72ef4 100644
--- a/src/character.cpp
+++ b/src/character.cpp
@@ -8305,26 +8305,26 @@ int Character::bonus_item_warmth( body_part bp ) const
 bool Character::can_use_floor_warmth() const
 {
     return in_sleep_state() ||
-           has_activity( activity_id( "ACT_WAIT" ) ) ||
-           has_activity( activity_id( "ACT_WAIT_NPC" ) ) ||
-           has_activity( activity_id( "ACT_WAIT_STAMINA" ) ) ||
-           has_activity( activity_id( "ACT_AUTODRIVE" ) ) ||
-           has_activity( activity_id( "ACT_READ" ) ) ||
-           has_activity( activity_id( "ACT_SOCIALIZE" ) ) ||
-           has_activity( activity_id( "ACT_MEDITATE" ) ) ||
-           has_activity( activity_id( "ACT_FISH" ) ) ||
-           has_activity( activity_id( "ACT_GAME" ) ) ||
-           has_activity( activity_id( "ACT_HAND_CRANK" ) ) ||
-           has_activity( activity_id( "ACT_HEATING" ) ) ||
-           has_activity( activity_id( "ACT_VIBE" ) ) ||
-           has_activity( activity_id( "ACT_TRY_SLEEP" ) ) ||
-           has_activity( activity_id( "ACT_OPERATION" ) ) ||
-           has_activity( activity_id( "ACT_TREE_COMMUNION" ) ) ||
-           has_activity( activity_id( "ACT_EAT_MENU" ) ) ||
-           has_activity( activity_id( "ACT_CONSUME_FOOD_MENU" ) ) ||
-           has_activity( activity_id( "ACT_CONSUME_DRINK_MENU" ) ) ||
-           has_activity( activity_id( "ACT_CONSUME_MEDS_MENU" ) ) ||
-           has_activity( activity_id( "ACT_STUDY_SPELL" ) );
+           has_activity( ACT_WAIT ) ||
+           has_activity( ACT_WAIT_NPC ) ||
+           has_activity( ACT_WAIT_STAMINA ) ||
+           has_activity( ACT_AUTODRIVE ) ||
+           has_activity( ACT_READ ) ||
+           has_activity( ACT_SOCIALIZE ) ||
+           has_activity( ACT_MEDITATE ) ||
+           has_activity( ACT_FISH ) ||
+           has_activity( ACT_GAME ) ||
+           has_activity( ACT_HAND_CRANK ) ||
+           has_activity( ACT_HEATING ) ||
+           has_activity( ACT_VIBE ) ||
+           has_activity( ACT_TRY_SLEEP ) ||
+           has_activity( ACT_OPERATION ) ||
+           has_activity( ACT_TREE_COMMUNION ) ||
+           has_activity( ACT_EAT_MENU ) ||
+           has_activity( ACT_CONSUME_FOOD_MENU ) ||
+           has_activity( ACT_CONSUME_DRINK_MENU ) ||
+           has_activity( ACT_CONSUME_MEDS_MENU ) ||
+           has_activity( ACT_STUDY_SPELL );
 }
 
 int Character::floor_bedding_warmth( const tripoint &pos )
diff --git a/src/game.cpp b/src/game.cpp
index d83c37bf18dba..6dd356f08eb71 100644
--- a/src/game.cpp
+++ b/src/game.cpp
@@ -8366,7 +8366,7 @@ void game::reload_weapon( bool try_everything )
     if( veh && ( turret = veh->turret_query( u.pos() ) ) && turret.can_reload() ) {
         item::reload_option opt = g->u.select_ammo( *turret.base(), true );
         if( opt ) {
-            g->u.assign_activity( activity_id( "ACT_RELOAD" ), opt.moves(), opt.qty() );
+            g->u.assign_activity( activity_id( ACT_RELOAD ), opt.moves(), opt.qty() );
             g->u.activity.targets.emplace_back( turret.base() );
             g->u.activity.targets.push_back( std::move( opt.ammo ) );
         }
diff --git a/src/handle_liquid.cpp b/src/handle_liquid.cpp
index cfdad43df3832..029c6922cbe37 100644
--- a/src/handle_liquid.cpp
+++ b/src/handle_liquid.cpp
@@ -33,6 +33,7 @@
 #include "optional.h"
 #include "player_activity.h"
 #include "string_formatter.h"
+#include "cata_string_consts.h"
 
 #define dbg(x) DebugLog((x),D_GAME) << __FILE__ << ":" << __LINE__ << ": "
 
@@ -301,11 +302,11 @@ static bool perform_liquid_transfer( item &liquid, const tripoint *const source_
 
     const auto create_activity = [&]() {
         if( source_veh != nullptr ) {
-            g->u.assign_activity( activity_id( "ACT_FILL_LIQUID" ) );
+            g->u.assign_activity( ACT_FILL_LIQUID );
             serialize_liquid_source( g->u.activity, *source_veh, part_num, liquid );
             return true;
         } else if( source_pos != nullptr ) {
-            g->u.assign_activity( activity_id( "ACT_FILL_LIQUID" ) );
+            g->u.assign_activity( ACT_FILL_LIQUID );
             serialize_liquid_source( g->u.activity, *source_pos, liquid );
             return true;
         } else if( source_mon != nullptr ) {
diff --git a/src/iexamine.cpp b/src/iexamine.cpp
index 896133d0363c3..834196bc4e720 100644
--- a/src/iexamine.cpp
+++ b/src/iexamine.cpp
@@ -5649,7 +5649,7 @@ void iexamine::workbench_internal( player &p, const tripoint &examp,
                 pgettext( "in progress craft", "You start working on the %s." ),
                 pgettext( "in progress craft", "<npcname> starts working on the %s." ),
                 selected_craft->tname() );
-            p.assign_activity( activity_id( "ACT_CRAFT" ) );
+            p.assign_activity( ACT_CRAFT );
             p.activity.targets.push_back( crafts[amenu2.ret] );
             p.activity.values.push_back( 0 ); // Not a long craft
             break;
diff --git a/src/iuse_actor.cpp b/src/iuse_actor.cpp
index 7dce0e9dd9fef..cac466d0b8552 100644
--- a/src/iuse_actor.cpp
+++ b/src/iuse_actor.cpp
@@ -812,7 +812,7 @@ int place_monster_iuse::use( player &p, item &it, bool, const tripoint & ) const
         newmon.friendly = -1;
     }
     // TODO: add a flag instead of monster id or something?
-    if( newmon.type->id == mtype_id( "mon_laserturret" ) && !g->is_in_sunlight( newmon.pos() ) ) {
+    if( newmon.type->id == mon_laserturret && !g->is_in_sunlight( newmon.pos() ) ) {
         p.add_msg_if_player( _( "A flashing LED on the laser turret appears to indicate low light." ) );
     }
     return 1;
diff --git a/src/monstergenerator.cpp b/src/monstergenerator.cpp
index 810c5750ec77a..c034b8c163e66 100644
--- a/src/monstergenerator.cpp
+++ b/src/monstergenerator.cpp
@@ -26,6 +26,7 @@
 #include "pathfinding.h"
 #include "units.h"
 #include "translations.h"
+#include "cata_string_consts.h"
 
 namespace io
 {
@@ -1100,7 +1101,7 @@ void mtype::remove_special_attacks( const JsonObject &jo, const std::string &mem
 void MonsterGenerator::check_monster_definitions() const
 {
     for( const auto &mon : mon_templates->get_all() ) {
-        if( mon.harvest == "null" && !mon.has_flag( MF_ELECTRONIC ) && mon.id != mtype_id( "mon_null" ) ) {
+        if( mon.harvest == "null" && !mon.has_flag( MF_ELECTRONIC ) && mon.id != mon_null ) {
             debugmsg( "monster %s has no harvest entry", mon.id.c_str(), mon.harvest.c_str() );
         }
         for( auto &spec : mon.species ) {
diff --git a/src/mutation.cpp b/src/mutation.cpp
index 6946186c946d0..09dccd52a9188 100644
--- a/src/mutation.cpp
+++ b/src/mutation.cpp
@@ -440,7 +440,7 @@ void Character::activate_mutation( const trait_id &mut )
         invoke_item( &burrowing_item );
         return;  // handled when the activity finishes
     } else if( mut == trait_SLIMESPAWNER ) {
-        monster *const slime = g->place_critter_around( mtype_id( "mon_player_blob" ), pos(), 1 );
+        monster *const slime = g->place_critter_around( mon_player_blob, pos(), 1 );
         if( !slime ) {
             // Oops, no room to divide!
             add_msg_if_player( m_bad, _( "You focus, but are too hemmed in to birth a new slimespring!" ) );
diff --git a/src/overmap.cpp b/src/overmap.cpp
index df7f210733ef9..30cc780b3707e 100644
--- a/src/overmap.cpp
+++ b/src/overmap.cpp
@@ -1983,7 +1983,7 @@ void overmap::move_hordes()
             auto &type = *( this_monster.type );
             if(
                 !type.species.count( ZOMBIE ) || // Only add zombies to hordes.
-                type.id == mtype_id( "mon_jabberwock" ) || // Jabberwockies are an exception.
+                type.id == mon_jabberwock || // Jabberwockies are an exception.
                 this_monster.get_speed() <= 30 || // So are very slow zombies, like crawling zombies.
                 this_monster.has_effect( effect_pet ) || // "Zombie pet" zlaves are, too.
                 !this_monster.will_join_horde( INT_MAX ) || // So are zombies who won't join a horde of any size.
diff --git a/src/player.cpp b/src/player.cpp
index 8c97dc1a1610e..bae48f2461bff 100644
--- a/src/player.cpp
+++ b/src/player.cpp
@@ -3173,25 +3173,25 @@ bool player::unwield()
 
 // ids of martial art styles that are available with the bio_cqb bionic.
 static const std::vector<matype_id> bio_cqb_styles{ {
-        matype_id{ "style_aikido" },
-        matype_id{ "style_biojutsu" },
-        matype_id{ "style_boxing" },
-        matype_id{ "style_capoeira" },
-        matype_id{ "style_crane" },
-        matype_id{ "style_dragon" },
-        matype_id{ "style_judo" },
-        matype_id{ "style_karate" },
-        matype_id{ "style_krav_maga" },
-        matype_id{ "style_leopard" },
-        matype_id{ "style_muay_thai" },
-        matype_id{ "style_ninjutsu" },
-        matype_id{ "style_pankration" },
-        matype_id{ "style_snake" },
-        matype_id{ "style_taekwondo" },
-        matype_id{ "style_tai_chi" },
-        matype_id{ "style_tiger" },
-        matype_id{ "style_wingchun" },
-        matype_id{ "style_zui_quan" }
+        style_aikido,
+        style_biojutsu,
+        style_boxing,
+        style_capoeira,
+        style_crane,
+        style_dragon,
+        style_judo,
+        style_karate,
+        style_krav_maga,
+        style_leopard,
+        style_muay_thai,
+        style_ninjutsu,
+        style_pankration,
+        style_snake,
+        style_taekwondo,
+        style_tai_chi,
+        style_tiger,
+        style_wingchun,
+        style_zui_quan
     }};
 
 bool character_martial_arts::pick_style( const avatar &you ) // Style selection menu
@@ -3427,7 +3427,7 @@ void player::mend_item( item_location &&obj, bool interactive )
         }
 
         const mending_method &method = opt.method;
-        assign_activity( activity_id( "ACT_MEND_ITEM" ), to_moves<int>( method.time ) );
+        assign_activity( ACT_MEND_ITEM, to_moves<int>( method.time ) );
         activity.name = opt.fault.str();
         activity.str_values.emplace_back( method.id );
         activity.targets.push_back( std::move( obj ) );
@@ -3728,7 +3728,7 @@ bool player::unload( item &it )
     } );
 
     if( target->is_magazine() ) {
-        player_activity unload_mag_act( activity_id( "ACT_UNLOAD_MAG" ) );
+        player_activity unload_mag_act( ACT_UNLOAD_MAG );
         assign_activity( unload_mag_act );
         activity.targets.emplace_back( item_location( *this, target ) );
 
@@ -4161,7 +4161,7 @@ void player::gunmod_add( item &gun, item &mod )
 
     const int moves = !has_trait( trait_DEBUG_HS ) ? mod.type->gunmod->install_time : 0;
 
-    assign_activity( activity_id( "ACT_GUNMOD_ADD" ), moves, -1, get_item_position( &gun ), tool );
+    assign_activity( ACT_GUNMOD_ADD, moves, -1, get_item_position( &gun ), tool );
     activity.values.push_back( get_item_position( &mod ) );
     activity.values.push_back( roll ); // chance of success (%)
     activity.values.push_back( risk ); // chance of damage (%)
@@ -4186,7 +4186,7 @@ void player::toolmod_add( item_location tool, item_location mod )
         return; // player canceled installation
     }
 
-    assign_activity( activity_id( "ACT_TOOLMOD_ADD" ), 1, -1 );
+    assign_activity( ACT_TOOLMOD_ADD, 1, -1 );
     activity.targets.emplace_back( std::move( tool ) );
     activity.targets.emplace_back( std::move( mod ) );
 }
@@ -4445,7 +4445,7 @@ void player::try_to_sleep( const time_duration &dur )
             add_msg_if_player( m_bad, _( "Your soporific inducer doesn't have enough power to operate." ) );
         }
     }
-    assign_activity( activity_id( "ACT_TRY_SLEEP" ), to_moves<int>( dur ) );
+    assign_activity( ACT_TRY_SLEEP, to_moves<int>( dur ) );
 }
 
 int player::sleep_spot( const tripoint &p ) const
diff --git a/src/savegame_json.cpp b/src/savegame_json.cpp
index a5ae977b5eb5e..f985136ada60b 100644
--- a/src/savegame_json.cpp
+++ b/src/savegame_json.cpp
@@ -452,7 +452,7 @@ void Character::load( const JsonObject &data )
         matype_id temp_selected_style;
         data.read( "style_selected", temp_selected_style );
         if( !temp_selected_style.is_valid() ) {
-            temp_selected_style = matype_id( "style_none" );
+            temp_selected_style = style_none;
         }
         martial_arts_data = character_martial_arts( temp_styles, temp_selected_style,
                             temp_keep_hands_free );
@@ -481,8 +481,8 @@ void Character::load( const JsonObject &data )
         backlog.push_front( temp );
     }
     if( !backlog.empty() && !backlog.front().str_values.empty() && ( ( activity &&
-            activity.id() == activity_id( "ACT_FETCH_REQUIRED" ) ) || ( destination_activity &&
-                    destination_activity.id() == activity_id( "ACT_FETCH_REQUIRED" ) ) ) ) {
+            activity.id() == ACT_FETCH_REQUIRED ) || ( destination_activity &&
+                    destination_activity.id() == ACT_FETCH_REQUIRED ) ) ) {
         requirement_data fetch_reqs;
         data.read( "fetch_data", fetch_reqs );
         const requirement_id req_id( backlog.front().str_values.back() );
@@ -718,8 +718,8 @@ void Character::store( JsonOut &json ) const
 
     // handling for storing activity requirements
     if( !backlog.empty() && !backlog.front().str_values.empty() && ( ( activity &&
-            activity.id() == activity_id( "ACT_FETCH_REQUIRED" ) ) || ( destination_activity &&
-                    destination_activity.id() == activity_id( "ACT_FETCH_REQUIRED" ) ) ) ) {
+            activity.id() == ACT_FETCH_REQUIRED ) || ( destination_activity &&
+                    destination_activity.id() == ACT_FETCH_REQUIRED ) ) ) {
         requirement_data things_to_fetch = requirement_id( backlog.front().str_values.back() ).obj();
         json.member( "fetch_data", things_to_fetch );
     }
diff --git a/src/savegame_legacy.cpp b/src/savegame_legacy.cpp
index 3ce600378503b..7ed52c4f3c9ab 100644
--- a/src/savegame_legacy.cpp
+++ b/src/savegame_legacy.cpp
@@ -29,6 +29,7 @@
 #include "type_id.h"
 #include "flat_set.h"
 #include "point.h"
+#include "cata_string_consts.h"
 
 namespace std
 {
@@ -197,49 +198,49 @@ void player_activity::deserialize_legacy_type( int legacy_type, activity_id &des
 {
     static const std::vector< activity_id > legacy_map = {
         activity_id::NULL_ID(),
-        activity_id( "ACT_RELOAD" ),
-        activity_id( "ACT_READ" ),
-        activity_id( "ACT_GAME" ),
-        activity_id( "ACT_WAIT" ),
-        activity_id( "ACT_CRAFT" ),
+        ACT_RELOAD,
+        ACT_READ,
+        ACT_GAME,
+        ACT_WAIT,
+        ACT_CRAFT,
         activity_id::NULL_ID(), // ACT_LONGCRAFT is deprecated
-        activity_id( "ACT_DISASSEMBLE" ),
-        activity_id( "ACT_BUTCHER" ),
-        activity_id( "ACT_LONGSALVAGE" ),
-        activity_id( "ACT_FORAGE" ),
-        activity_id( "ACT_BUILD" ),
-        activity_id( "ACT_VEHICLE" ),
+        ACT_DISASSEMBLE,
+        ACT_BUTCHER,
+        ACT_LONGSALVAGE,
+        ACT_FORAGE,
+        ACT_BUILD,
+        ACT_VEHICLE,
         activity_id::NULL_ID(), // ACT_REFILL_VEHICLE is deprecated
-        activity_id( "ACT_TRAIN" ),
-        activity_id( "ACT_WAIT_WEATHER" ),
-        activity_id( "ACT_FIRSTAID" ),
-        activity_id( "ACT_FISH" ),
-        activity_id( "ACT_PICKAXE" ),
-        activity_id( "ACT_BURROW" ),
-        activity_id( "ACT_PULP" ),
-        activity_id( "ACT_VIBE" ),
-        activity_id( "ACT_MAKE_ZLAVE" ),
-        activity_id( "ACT_DROP" ),
-        activity_id( "ACT_STASH" ),
-        activity_id( "ACT_PICKUP" ),
-        activity_id( "ACT_MOVE_ITEMS" ),
-        activity_id( "ACT_ADV_INVENTORY" ),
-        activity_id( "ACT_ARMOR_LAYERS" ),
-        activity_id( "ACT_START_FIRE" ),
-        activity_id( "ACT_OPEN_GATE" ),
-        activity_id( "ACT_FILL_LIQUID" ),
-        activity_id( "ACT_HOTWIRE_CAR" ),
-        activity_id( "ACT_AIM" ),
-        activity_id( "ACT_ATM" ),
-        activity_id( "ACT_START_ENGINES" ),
-        activity_id( "ACT_OXYTORCH" ),
-        activity_id( "ACT_CRACKING" ),
-        activity_id( "ACT_REPAIR_ITEM" ),
-        activity_id( "ACT_MEND_ITEM" ),
-        activity_id( "ACT_GUNMOD_ADD" ),
-        activity_id( "ACT_WAIT_NPC" ),
-        activity_id( "ACT_CLEAR_RUBBLE" ),
-        activity_id( "ACT_MEDITATE" ),
+        ACT_TRAIN,
+        ACT_WAIT_WEATHER,
+        ACT_FIRSTAID,
+        ACT_FISH,
+        ACT_PICKAXE,
+        ACT_BURROW,
+        ACT_PULP,
+        ACT_VIBE,
+        ACT_MAKE_ZLAVE,
+        ACT_DROP,
+        ACT_STASH,
+        ACT_PICKUP,
+        ACT_MOVE_ITEMS,
+        ACT_ADV_INVENTORY,
+        ACT_ARMOR_LAYERS,
+        ACT_START_FIRE,
+        ACT_OPEN_GATE,
+        ACT_FILL_LIQUID,
+        ACT_HOTWIRE_CAR,
+        ACT_AIM,
+        ACT_ATM,
+        ACT_START_ENGINES,
+        ACT_OXYTORCH,
+        ACT_CRACKING,
+        ACT_REPAIR_ITEM,
+        ACT_MEND_ITEM,
+        ACT_GUNMOD_ADD,
+        ACT_WAIT_NPC,
+        ACT_CLEAR_RUBBLE,
+        ACT_MEDITATE,
         activity_id::NULL_ID() // NUM_ACTIVITIES
     };