1. Integrate sensing blocks into conditionals

Sensing blocks (light blue) gather information about the environment, such as mouse coordinates, distance, keypresses, or collisions. To make a program react to this information, you place these sensing blocks inside the hexagon slot of conditional statement blocks, creating scripts that constantly monitor and respond to changes on the stage.

Sensing blocks are the eyes and ears of your code. By nesting them inside conditionals, you program your sprites to be aware of their surroundings, enabling interactions like opening doors or flashing warnings when coordinates cross.

2. Detect sprite-to-sprite collision events

Collision detection is a core mechanic in game design. Using the touching [sprite]? sensing block, a sprite can detect when its boundary overlaps with another sprite. For example, a player character touching a coin sprite can trigger a script that increases the score and hides the coin, or touching an enemy can trigger a 'game over' state.

Sprite collision calculations run in the background. The computer checks if any overlapping pixels exist between the two bounding boxes in each frame. If a collision is detected, it triggers the action pathway, allowing real-time combat or item gathering.

3. Detect boundary limits using color sensing

You can also detect boundaries using the touching color [ ]? block. This checks if any pixel of the sprite is overlapping with a specific color on the Stage backdrop. This is highly useful for coding boundary limits, walls in maze games, or track edges in racing games without needing complex coordinate math.

Color sensing is useful for complex maze paths. By setting the wall color once, you don't need to specify coordinates for every single wall. The sprite automatically blocks movement whenever it comes in contact with that color, simplifying maze construction.

4. Program immediate collision reactions

When a collision is detected, the program must respond. This reaction is coded inside the conditional statement. For example, if a player sprite touches a maze wall, the script can immediately reset its position to the starting coordinates or move it backward to block it from passing through the wall.

Reactions can be visual, auditory, or coordinate-based. Resetting coordinates to starting points creates a penalty for hit collisions. You can also play sound effects or reduce health stats to provide clear feedback to the player.