Developing a Game - Is there an unpredictable value before the block is generated?

I would like to pick several hash values from a specific block to be used as the game’s result. But I am less familiar with these fields, so could someone help me identify which hash values I can take and they should be unpredictable before the block is generated?

Is there any document to understand them?

RPC call get_block

{
    "block": {
        "challenge_chain_ip_proof": {
            "normalized_to_identity": false,
            "witness": "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",
            "witness_type": 2
        },
        "challenge_chain_sp_proof": {
            "normalized_to_identity": false,
            "witness": "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",
            "witness_type": 2
        },
        "finished_sub_slots": [],
        "foliage": {
            "foliage_block_data": {
                "extension_data": "0x0000000000000000000000000000000000000000000000000000000003a2c7c9",
                "farmer_reward_puzzle_hash": "0xff0a25ba03f357199e4e5b5372f02549c3e2c06aab14aaf44834ec5877c3d605",
                "pool_signature": null,
                "pool_target": {
                    "max_height": 0,
                    "puzzle_hash": "0x449636a16550171f0045cd69f552340346d5566420f8032f9d19987369fe967e"
                },
                "unfinished_reward_block_hash": "0xa839ca53a87aa4c74236801debb7aa925e83bd884842e58aa168ddb264f1594d"
            },
            "foliage_block_data_signature": "0xb1ee7073e26fdd50ca728d718fba17f6a5e835d5c6b983895f951872e0f3dde56337316d94a97f79391db4489fda3abf028e6e8f8b9561cfa784d58f69881b478db0956bc1f4fbb5c4daa50a14a2b60f0d0694e915ba0a330a09d14da0fe5b1c",
            "foliage_transaction_block_hash": null,
            "foliage_transaction_block_signature": null,
            "prev_block_hash": "0xc832dfd13119ddd8c48ae8e014e0cb9e66dca2668a663151deb985230e1cfa5e",
            "reward_block_hash": "0x7a1822c310e4d52648cef1eabf39b5547d206e8bd0301c1081f9941651324798"
        },
        "foliage_transaction_block": null,
        "infused_challenge_chain_ip_proof": {
            "normalized_to_identity": false,
            "witness": "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",
            "witness_type": 2
        },
        "reward_chain_block": {
            "challenge_chain_ip_vdf": {
                "challenge": "0xf7a1b55f90925d954d9b54797000e1b71c8b85fd41a4f9a23414d42b76965645",
                "number_of_iterations": 127901123,
                "output": {
                    "data": "0x0300ad61721839625a408d5921c9dfc44a26aa9473fce7e3ff066593a1730513d0fb8b3561825b4996b6749a0cd7bfd1a9af911c0f4f09d7a11d06ec06bb1f1d093c4e1b3807c30d502526bfb77e64bfa2f209e092b8f0f451d097e789f3c3a0461b0100"
                }
            },
            "challenge_chain_sp_signature": "0x8ea9523d80c3ba76cf263f5c900212a3b73420013ee3457fd50db8f4cec22db28f52700061c0422eed9027c2207a0c591283520058f7da127941da44b059920ffb8845014f11bd6d9e721309f85a02c12cad52a2bc3c4309df0e59c233f200b0",
            "challenge_chain_sp_vdf": {
                "challenge": "0xf7a1b55f90925d954d9b54797000e1b71c8b85fd41a4f9a23414d42b76965645",
                "number_of_iterations": 120193024,
                "output": {
                    "data": "0x01000d1b9111565b9ef2029f239ea306bf65f1012a60c1888f3a642e2383f281a4dd2fb5e62824e5ddf67934492f0412ae2201c0421e4a445bcd1a6e90d4ed374216dd511225bc2cbfa61d790f05d05c25dfbc06382919f35de1069c982209cc532a0100"
                }
            },
            "height": 2019492,
            "infused_challenge_chain_ip_vdf": {
                "challenge": "0x4e53cb08ca3811a4d7e86c79605b7f2aee79bf90cb68006354a336e2d9865fe4",
                "number_of_iterations": 768536,
                "output": {
                    "data": "0x01002f76d8ac9e87f41af9d95b75167ba131cacd7610aecb7a112ee2ad24092e87252c3ffebf6bdd1f279d56ba38faefd3af665e2a08203472e09c41601af65061098d9214878bcd60d5633fa1c89e44b556725ca9db5e1df7371cc1d1087a1306030701"
                }
            },
            "is_transaction_block": false,
            "pos_ss_cc_challenge_hash": "0xf7a1b55f90925d954d9b54797000e1b71c8b85fd41a4f9a23414d42b76965645",
            "proof_of_space": {
                "challenge": "0xd190e4634e06ef7aa976e959ef8575be9e25672850c08db618962110e3aaeb4a",
                "plot_public_key": "0xb503d8b71f15c6195da1f060fe5689aab510b72e760b243c4950d82aff8fd5358d06d9fd0226449bc54fd04e657b2185",
                "pool_contract_puzzle_hash": "0x449636a16550171f0045cd69f552340346d5566420f8032f9d19987369fe967e",
                "pool_public_key": null,
                "proof": "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",
                "size": 32
            },
            "reward_chain_ip_vdf": {
                "challenge": "0x2318f9df0b32f4cdbca1e12476f7071ade63b8eef5616df0e4ffc51d5bcabe8d",
                "number_of_iterations": 768536,
                "output": {
                    "data": "0x000098b6a051817c75e7cfad72374e268f686761856b68bfe6cc1c3e4b96a6dbdc757806003101e074c156622b8f9d5fefe127ad633b87c9668a81ca1e00af98eb752f64561b53f088bf01577ffb51e2f460bf27a9138995814b501574a172eb87680100"
                }
            },
            "reward_chain_sp_signature": "0x83a57e5a87492bd7deb0a7e604852a77b7c2a05ebfdcf31df6910e43333af5d7b13afe87115c44be95f3b74f1d7761f10fa1a608fac4a4fad340eecaba7ac054bcf21580319973755420889ae844f08801404f421437ab61856950e656c8653f",
            "reward_chain_sp_vdf": {
                "challenge": "0x50469b00663c8a9fb0401f9ea5824feaca148de92d69434933c2057cf2016a0d",
                "number_of_iterations": 2299007,
                "output": {
                    "data": "0x0200bedc4c9cf886fdbcc431627be3a987d1ee1087a2a3dce360ee2dc014b8c326c6939bbf308b81068ef3b87d64b99d04ae64b2a3aef0769c8021fb83a0a062ba1545d145bde9044629954bb199828a04cd846faf3b21ae3f95d52de64ce501a3050500"
                }
            },
            "signage_point_index": 56,
            "total_iters": 8011343961539,
            "weight": 4319756560
        },
        "reward_chain_ip_proof": {
            "normalized_to_identity": false,
            "witness": "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",
            "witness_type": 2
        },
        "reward_chain_sp_proof": {
            "normalized_to_identity": false,
            "witness": "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",
            "witness_type": 2
        },
        "transactions_generator": null,
        "transactions_generator_ref_list": [],
        "transactions_info": null
    },
    "success": true
}